A222405 Triangle read by rows: left and right edges are A002061 (1,3,7,13,21,...), interior entries are filled in using the Pascal triangle rule.

1, 3, 3, 7, 6, 7, 13, 13, 13, 13, 21, 26, 26, 26, 21, 31, 47, 52, 52, 47, 31, 43, 78, 99, 104, 99, 78, 43, 57, 121, 177, 203, 203, 177, 121, 57, 73, 178, 298, 380, 406, 380, 298, 178, 73, 91, 251, 476, 678, 786, 786, 678, 476, 251, 91, 111, 342, 727, 1154, 1464, 1572, 1464, 1154, 727, 342, 111

Offset

0,2

Links

Table of n, a(n) for n=0..65.

Example

Triangle begins:
1
3, 3
7, 6, 7
13, 13, 13, 13
21, 26, 26, 26, 21
31, 47, 52, 52, 47, 31
43, 78, 99, 104, 99, 78, 43
57, 121, 177, 203, 203, 177, 121, 57
73, 178, 298, 380, 406, 380, 298, 178, 73
...

Maple

d:=[seq(n*(n+1)+1, n=0..14)];
f:=proc(d) local T, M, n, i;
M:=nops(d);
T:=Array(0..M-1, 0..M-1);
for n from 0 to M-1 do T[n, 0]:=d[n+1]; T[n, n]:=d[n+1]; od:
for n from 2 to M-1 do
for i from 1 to n-1 do T[n, i]:=T[n-1, i-1]+T[n-1, i]; od: od:
lprint("triangle:");
for n from 0 to M-1 do lprint(seq(T[n, i], i=0..n)); od:
lprint("row sums:");
lprint([seq( add(T[i, j], j=0..i), i=0..M-1)]);
end;
f(d);

Mathematica

t[n_, n_] := n^2+n+1; t[n_, 0] := n^2+n+1; t[n_, k_] := t[n, k] = t[n-1, k-1] + t[n-1, k]; Table[t[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 14 2014 *)

Crossrefs

Cf. A007318, A002061, A222403, A222404.

Row sums are A027178.

Sequence in context: A045773 A256700 A175039 * A146970 A078708 A096273

Adjacent sequences: A222402 A222403 A222404 * A222406 A222407 A222408

Keyword

nonn,tabl

Author

N. J. A. Sloane, Feb 18 2013

Status

approved