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Search: seq:1,0,1,1,1,1,2,2,2,1
Displaying 1-9 of 9 results found. page 1
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A089258 Transposed version of A080955: T(n,k) = A080955(k,n), n>=0, k>=-1. +30
7
1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 5, 6, 9, 1, 4, 10, 16, 24, 44, 1, 5, 17, 38, 65, 120, 265, 1, 6, 26, 78, 168, 326, 720, 1854, 1, 7, 37, 142, 393, 872, 1957, 5040, 14833, 1, 8, 50, 236, 824, 2208, 5296, 13700, 40320, 133496, 1, 9, 65, 366, 1569, 5144, 13977, 37200, 109601, 362880, 1334961 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,8
COMMENTS
Can be extended to columns with negative indices k<0 via T(n,k) = A292977(n,-k). - Max Alekseyev, Mar 06 2018
LINKS
FORMULA
For n > 0, k >= -1, T(n,k) is the permanent of the n X n matrix with k+1 on the diagonal and 1 elsewhere.
T(0,k) = 1.
T(n,k) = Sum_{j>=0} A008290(n,j) * (k+1)^j.
T(n,k) = n*T(n-1, k) + k^n .
T(n,k) = n! * Sum_{j=0..n} k^j/j!.
E.g.f. for k-th column: exp(k*x)/(1-x).
Assuming n >= 0, k >= 0: T(n, k) = exp(k-1)*Gamma(n+1, k-1). - Peter Luschny, Dec 24 2021
EXAMPLE
n\k -1 0 1 2 3 4 5 6 ...
----------------------------------------------
0 | 1, 1, 1, 1, 1, 1, 1, 1, ...
1 | 0, 1, 2, 3, 4, 5, 6, 7, ...
2 | 1, 2, 5, 10, 17, 26, 37, 50, ...
3 | 2, 6, 16, 38, 78, 152, 236, 366, ...
4 | 9, 24, 65, 168, 393, 824, 1569, 2760, ...
...
MATHEMATICA
(* Assuming offset (0, 0): *)
T[n_, k_] := Exp[k - 1] Gamma[n + 1, k - 1];
Table[T[k, n - k], {n, 0, 10}, {k, 0, n}] // Flatten (* Peter Luschny, Dec 24 2021 *)
CROSSREFS
Main diagonal gives A217701.
KEYWORD
easy,nonn,tabl
AUTHOR
Philippe Deléham, Dec 12 2003
EXTENSIONS
Edited and changed offset for k to -1 by Max Alekseyev, Mar 08 2018
STATUS
approved
A352682 Array read by ascending antidiagonals. A(n, k) = (n-1)*Gould(k-1) + Bell(k) for n >= 0 and k >= 1, A(n, 0) = 1. +30
6
1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 3, 5, 6, 1, 4, 4, 8, 15, 21, 1, 5, 5, 11, 24, 52, 82, 1, 6, 6, 14, 33, 83, 203, 354, 1, 7, 7, 17, 42, 114, 324, 877, 1671, 1, 8, 8, 20, 51, 145, 445, 1400, 4140, 8536, 1, 9, 9, 23, 60, 176, 566, 1923, 6609, 21147, 46814 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,8
COMMENTS
The array defines a family of Bell-like sequences. The case n = 1 are the Bell numbers A000110, case n = 0 is A032347 and case n = 2 is A038561. The n-th sequence r(k) = T(n, k) is defined for k >= 0 by the recurrence r(k) = Sum_{j=0..k-1} binomial(k-1, j)*r(j) with r(0) = 1 and r(1) = n.
LINKS
FORMULA
Given a list T let PS(T) denote the list of partial sums of T. Given two list S and T let [S, T] denote the concatenation of the lists. Further let P[end] denote the last element of the list P. Row n of the array with length k can be computed by the following procedure:
A = [n], P = [1], R = [1];
Repeat k-1 times: R = [R, A], P = PS([A, P]), A = [P[end]];
Return R.
EXAMPLE
Array starts:
n\k 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ...
---------------------------------------------------------
[0] 1, 0, 1, 2, 6, 21, 82, 354, 1671, 8536, ... A032347
[1] 1, 1, 2, 5, 15, 52, 203, 877, 4140, 21147, ... A000110
[2] 1, 2, 3, 8, 24, 83, 324, 1400, 6609, 33758, ... A038561
[3] 1, 3, 4, 11, 33, 114, 445, 1923, 9078, 46369, ... A038559
[4] 1, 4, 5, 14, 42, 145, 566, 2446, 11547, 58980, ... A352683
[5] 1, 5, 6, 17, 51, 176, 687, 2969, 14016, 71591, ...
[6] 1, 6, 7, 20, 60, 207, 808, 3492, 16485, 84202, ...
[7] 1, 7, 8, 23, 69, 238, 929, 4015, 18954, 96813, ...
[8] 1, 8, 9, 26, 78, 269, 1050, 4538, 21423, 109424, ...
[9] 1, 9, 10, 29, 87, 300, 1171, 5061, 23892, 122035, ...
MAPLE
alias(PS = ListTools:-PartialSums):
BellRow := proc(n, len) local a, k, P, T;
a := n; P := [1]; T := [1];
for k from 1 to len-1 do
T := [op(T), a]; P := PS([a, op(P)]); a := P[-1] od;
T end: seq(lprint(BellRow(n, 10)), n = 0..9);
MATHEMATICA
nmax = 10;
BellRow[n_, len_] := Module[{a, k, P, T}, a = n; P = {1}; T = {1};
For[k = 1, k <= len - 1, k++,
T = Append[T, a]; P = Accumulate[Join[{a}, P]]; a = P[[-1]]];
T];
rows = Table[BellRow[n, nmax + 1], {n, 0, nmax}];
A[n_, k_] := rows[[n + 1, k + 1]];
Table[A[n - k, k], {n, 0, nmax}, {k, 0, n}] // Flatten (* Jean-François Alcover, Apr 15 2024, after Peter Luschny *)
PROG
(Julia)
function BellRow(m, len)
a = m; P = BigInt[1]; T = BigInt[1]
for n in 1:len
T = vcat(T, a)
P = cumsum(vcat(a, P))
a = P[end]
end
T end
for n in 0:9 BellRow(n, 9) |> println end
CROSSREFS
Diagonals: A352684 (main).
Cf. A040027 (Gould), A352686 (subtriangle).
Compare A352680 for a similar array based on the Catalan numbers.
KEYWORD
nonn,tabl
AUTHOR
Peter Luschny, Mar 28 2022
STATUS
approved
A372014 T(n,k) is the total number of levels in all Motzkin paths of length n containing exactly k path nodes; triangle T(n,k), n>=0, 1<=k<=n+1, read by rows. +30
5
1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 4, 6, 4, 3, 1, 8, 14, 12, 7, 4, 1, 18, 32, 33, 21, 11, 5, 1, 44, 74, 84, 64, 34, 16, 6, 1, 113, 180, 208, 181, 111, 52, 22, 7, 1, 296, 457, 520, 485, 344, 179, 76, 29, 8, 1, 782, 1195, 1334, 1273, 1000, 599, 274, 107, 37, 9, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,7
COMMENTS
A Motzkin path of length n has n+1 nodes.
LINKS
Wikipedia, Motzkin number
FORMULA
Sum_{k=1..n+1} k * T(n,k) = A005717(n+1) = (n+1) * A001006(n).
EXAMPLE
In the A001006(3) = 4 Motzkin paths of length 3 there are 2 levels with 1 node, 2 levels with 2 nodes, 2 levels with 3 nodes, and 1 level with 4 nodes.
2 _ 1 1
2 / \ 3 /\_ 3 _/\ 4 ___ .
So row 3 is [2, 2, 2, 1].
Triangle T(n,k) begins:
1;
0, 1;
1, 1, 1;
2, 2, 2, 1;
4, 6, 4, 3, 1;
8, 14, 12, 7, 4, 1;
18, 32, 33, 21, 11, 5, 1;
44, 74, 84, 64, 34, 16, 6, 1;
113, 180, 208, 181, 111, 52, 22, 7, 1;
296, 457, 520, 485, 344, 179, 76, 29, 8, 1;
782, 1195, 1334, 1273, 1000, 599, 274, 107, 37, 9, 1;
...
MAPLE
g:= proc(x, y, p) (h-> `if`(x=0, add(z^coeff(h, z, i)
, i=0..degree(h)), b(x, y, h)))(p+z^y) end:
b:= proc(x, y, p) option remember; `if`(y+2<=x, g(x-1, y+1, p), 0)
+`if`(y+1<=x, g(x-1, y, p), 0)+`if`(y>0, g(x-1, y-1, p), 0)
end:
T:= n-> (p-> seq(coeff(p, z, i), i=1..n+1))(g(n, 0$2)):
seq(T(n), n=0..10);
CROSSREFS
Columns k=1-2 give: A088457, A051485.
Row sums give A372033 = A001006 + A333498.
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Apr 15 2024
STATUS
approved
A194821 a(n) = 1+floor(sum{<((-1)^k)*k*sqrt(2)> : 1<=k<=n}), where < > = fractional part. +30
4
0, 1, 1, 1, 1, 2, 1, 1, 0, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 2, 2, 1, 2, 1, 2, 2, 2, 2, 3, 2, 2, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 1, 2, 1, 1, 0, 1, 0, 1, 1, 1, 1, 2, 1, 1, 0, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 2, 2, 1, 2, 1, 2, 2, 2, 2, 3, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
COMMENTS
Does 0 occur infinitely many times? Is the sequence unbounded?
LINKS
MATHEMATICA
r = Sqrt[2]; p[x_] := FractionalPart[x];
f[n_] := 1 + Floor[Sum[p[k*r] (-1)^k, {k, 1, n}]]
Table[f[n], {n, 1, 100}] (* A194821 *)
PROG
(PARI) for(n=1, 50, print1(1 + floor(sum(k=1, n, (-1)^k*frac(k*sqrt(2))), ", ")) \\ G. C. Greubel, Apr 02 2018
(Magma) [1 + Floor((&+[(-1)^k*(k*Sqrt(2) - Floor(k*Sqrt(2))) :k in [1..n]])) : n in [1..50]]; // G. C. Greubel, Apr 02 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Sep 03 2011
STATUS
approved
A264051 Triangle read by rows: T(n,k) (n>=0, 0<=k<=A264078(n)) is the number of integer partitions of n having k standard Young tableaux such that no entries i and i+1 appear in the same row. +30
3
0, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 2, 3, 0, 2, 4, 2, 1, 1, 1, 1, 1, 4, 3, 1, 0, 0, 2, 2, 0, 1, 0, 1, 0, 0, 0, 1, 7, 2, 0, 0, 1, 0, 3, 0, 1, 0, 2, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 7, 3, 1, 2, 0, 0, 1, 2, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,8
COMMENTS
Row sums give A000041.
Column k=0 gives A025065(n-2) for n>=2.
LINKS
S. Dulucq and O. Guibert, Stack words, standard tableaux and Baxter permutations, Disc. Math. 157 (1996), 91-106.
FORMULA
Sum_{k=1..A264078(n)} k*T(n,k) = A237770(n). - Alois P. Heinz, Nov 02 2015
EXAMPLE
Triangle begins:
0,1,
0,1,
1,1,
1,2,
2,2,1,
2,3,0,2,
4,2,1,1,1,1,1,
4,3,1,0,0,2,2,0,1,0,1,0,0,0,1,
7,2,0,0,1,0,3,0,1,0,2,1,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,1,0,1,
...
MAPLE
h:= proc(l, j) option remember; `if`(l=[], 1,
`if`(l[1]=0, h(subsop(1=[][], l), j-1), add(
`if`(i<>j and l[i]>0 and (i=1 or l[i]>l[i-1]),
h(subsop(i=l[i]-1, l), i), 0), i=1..nops(l))))
end:
g:= proc(n, i, l) `if`(n=0 or i=1, x^h([1$n, l[]], 0),
`if`(i<1, 0, g(n, i-1, l)+ `if`(i>n, 0,
g(n-i, i, [i, l[]]))))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(g(n$2, [])):
seq(T(n), n=0..10); # Alois P. Heinz, Nov 02 2015
MATHEMATICA
h[l_, j_] := h[l, j] = If[l == {}, 1, If[l[[1]] == 0, h[ReplacePart[l, 1 -> Sequence[]], j - 1], Sum[If[i != j && l[[i]] > 0 && (i == 1 || l[[i]] > l[[i - 1]]), h[ReplacePart[l, i -> l[[i]] - 1], i], 0], {i, 1, Length[l]} ]]]; g[n_, i_, l_] := If[n == 0 || i == 1, x^h[Join[Array[1 &, n], l], 0], If[i < 1, 0, g[n, i - 1, l] + If[i > n, 0, g[n - i, i, Join[{i}, l]]] ]]; T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, Exponent[p, x]}]][g[n, n, {}]]; Table[T[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Jan 22 2016, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Christian Stump, Nov 01 2015
STATUS
approved
A356997 a(n) = b(n) - b(n - b(n - b(n))) for n >= 2, where b(n) = A356988(n). +30
2
0, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 1, 2, 3, 3, 3, 3, 3, 2, 2, 2, 3, 4, 5, 5, 5, 5, 5, 5, 5, 4, 3, 3, 3, 3, 4, 5, 6, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 7, 6, 5, 5, 5, 5, 5, 5, 6, 7, 8, 9, 10, 11, 12, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 12, 11, 10, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 10, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,9
COMMENTS
The line graph of the sequence consists of a series of local plateaus and local troughs joined at each end by lines of slope 1 and slope -1. More precisely, for k >= 3 the graph of the sequence consists of
local plateaus: on the integer interval [2*F(k), 2*F(k) + 2*F(k-3)] the sequence has the constant value F(k-2)
descent to a trough: on the integer interval [2*F(k) + 2*F(k-3), F(k+2)] the line graph of the sequence has slope -1
local troughs: on the integer interval [F(k+2), F(k+2) + F(k-3)] the sequence has the constant value F(k-3)
ascent to a plateau: on the integer interval [F(k+2) + F(k-3), 2*F(k+1)] the line graph of the sequence has slope 1.
LINKS
FORMULA
a(n+1) - a(n) = 1, 0 or -1.
Let F(n) = A000045(n) with F(-1) = 1 and let L(n) = A000032(n).
For k >= 5, a(F(k) + j) = F(k-5) for 0 <= j <= F(k-5) (troughs).
For k >= 4, a(2*F(k) + j) = F(k-2) for 0 <= j <= 2*F(k-3) (plateaus).
EXAMPLE
The sequence is arranged to show the local plateaus (P) and the local troughs (T):
0,
1,
1,
T 0,
P 1, 1, 1
1,
P 2, 2, 2,
T 1,1,
2,
P 3, 3, 3, 3, 3,
T 2, 2, 2,
3,
4,
P 5, 5, 5, 5, 5, 5, 5,
4,
T 3, 3, 3, 3,
4,
5,
6,
7,
P 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
7,
6,
T 5, 5, 5, 5, 5, 5,
6,
7,
8,
9,
10,
11,
12,
P 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
12,
11,
10,
9,
T 8, 8, 8, 8, 8, 8, 8, 8, 8,
9,
10,
11,
...
MAPLE
# b(n) = A356988
b := proc(n) option remember; if n = 1 then 1 else n - b(b(n - b(b(b(n-1))))) end if; end proc:
seq( b(n) - b(n - b(n - b(n))), n = 2
..100);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Peter Bala, Sep 11 2022
STATUS
approved
A124369 Riordan array (1/((1-x-x^2)(1+x+x^2)),x(1+x)/((1-x-x^2)(1+x+x^2))). +30
1
1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 2, 6, 4, 3, 1, 4, 9, 12, 7, 4, 1, 7, 17, 24, 21, 11, 5, 1, 10, 34, 48, 50, 34, 16, 6, 1, 17, 58, 103, 110, 91, 52, 22, 7, 1, 28, 104, 200, 250, 220, 152, 76, 29, 8, 1, 44, 188, 385, 534, 530, 400, 239, 107, 37, 9, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,7
COMMENTS
Row sums are A123392. Diagonal sums are A124370. First column is A094686. Product of A026729 and abs(A049310).
LINKS
FORMULA
Number triangle T(n,k)=sum{j=0..n, C(j,n-j)*C((j+k)/2,(j-k)/2)*(1+(-1)^(j-k))/2};
T(n,k) = T(n-1,k-1) + T(n-2,k) + T(n-2,k-1) + 2*T(n-3,k) + T(n-4,k), T(0,0) = 1, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Jan 22 2014
EXAMPLE
Triangle begins
1,
0, 1,
1, 1, 1,
2, 2, 2, 1,
2, 6, 4, 3, 1,
4, 9, 12, 7, 4, 1,
7, 17, 24, 21, 11, 5, 1,
10, 34, 48, 50, 34, 16, 6, 1,
17, 58, 103, 110, 91, 52, 22, 7, 1
KEYWORD
easy,nonn,tabl
AUTHOR
Paul Barry, Oct 27 2006
STATUS
approved
A105241 Vector triangular array of Fibonacci tensor Markov. +30
0
0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 2, 2, 2, 4, 3, 3, 1, 4, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,16
COMMENTS
This is the triangle form from {6,2,2}. T[n,k,j] levels j: {0, 1, 1, 1} {0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2} {0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3} {0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 2, 2, 2, 4, 3, 3, 1, 4}
LINKS
FORMULA
v[n]=M.v[n-1] M={M1, M2} M1={{0, 1}, {1, 0}} M2={{0, 1}, {1, 1}} Selective flattening and expression to get a vector triangle representation =a[n]
MATHEMATICA
v[1] = {{0, 1}, {1, 1}} M = {{{0, 1}, {1, 1}}, {{0, 1}, {1, 1}}} v[n_] := v[n] = M.v[n - 1] a = Table[v[n], {n, 1, 6}] Dimensions[a aa = Table[Flatten[Table[Table[a[[n, j]], {j, 1, 2}], {n, 1, m}]], {m, 1, 6}] aout= Flatten[aa]
KEYWORD
nonn,uned,obsc
AUTHOR
Roger L. Bagula, Apr 12 2005
STATUS
approved
A105242 A nonsense sequence. +30
0
0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 2, 2, 2, 4, 3, 3, 1, 4, 1, 1, 1, 2, 2, 2, 1, 3, 2, 2, 2, 4, 3, 3, 1, 4, 1, 1, 1, 2, 2, 2, 1, 3, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 2, 2, 2, 4, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,12
LINKS
MATHEMATICA
v[1] = {{0, 1}, {1, 1}}
M = {{{0, 1}, {1, 0}}, {{0, 1}, {1, 1}}}
v[n_] := v[n] = M.v[n - 1]
a = Table[v[n], {n, 1, 6}]
aa = Flatten[a]
Length[aa]
KEYWORD
nonn,uned,obsc,less
AUTHOR
Roger L. Bagula, Apr 12 2005
STATUS
approved
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Last modified August 7 17:47 EDT 2024. Contains 375017 sequences. (Running on oeis4.)