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A326500 Number T(n,k) of colored integer partitions of n using all colors of a k-set such that each block of part i with multiplicity j has a pattern of i*j colors in (weakly) increasing order; triangle T(n,k), n>=0, 0<=k<=n, read by rows. 5

%I #38 Apr 30 2020 11:36:23

%S 1,0,1,0,2,2,0,3,8,5,0,5,22,30,13,0,7,54,129,124,42,0,11,118,428,696,

%T 525,150,0,15,248,1293,3108,3830,2358,576,0,22,490,3483,11595,20720,

%U 20535,10661,2266,0,30,950,9102,40592,99140,141234,117362,52824,9966

%N Number T(n,k) of colored integer partitions of n using all colors of a k-set such that each block of part i with multiplicity j has a pattern of i*j colors in (weakly) increasing order; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

%H Alois P. Heinz, <a href="/A326500/b326500.txt">Rows n = 1..140, flattened</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_(number_theory)">Partition (number theory)</a>

%F Sum_{k=1..n} k * T(n,k) = A326656(n).

%e T(3,1) = 3: 3aaa, 2aa1a, 111aaa.

%e T(3,2) = 8: 3aab, 3abb, 2aa1b, 2ab1b, 2ab1a, 2bb1a, 111aab, 111abb.

%e T(3,3) = 5: 3abc, 2ab1c, 2ac1b, 2bc1a, 111abc.

%e Triangle T(n,k) begins:

%e 1;

%e 0, 1;

%e 0, 2, 2;

%e 0, 3, 8, 5;

%e 0, 5, 22, 30, 13;

%e 0, 7, 54, 129, 124, 42;

%e 0, 11, 118, 428, 696, 525, 150;

%e 0, 15, 248, 1293, 3108, 3830, 2358, 576;

%e 0, 22, 490, 3483, 11595, 20720, 20535, 10661, 2266;

%e 0, 30, 950, 9102, 40592, 99140, 141234, 117362, 52824, 9966;

%e ...

%p b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, add((t->

%p b(n-t, min(n-t, i-1), k)*binomial(k+t-1, t))(i*j), j=0..n/i)))

%p end:

%p T:= (n, k)-> add(b(n$2, k-i)*(-1)^i*binomial(k, i), i=0..k):

%p seq(seq(T(n, k), k=0..n), n=0..12);

%t b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i < 1, 0, Sum[Function[t, b[n-t, Min[n-t, i-1], k] Binomial[k + t - 1, t]][i j], {j, 0, n/i}]]];

%t T[n_, k_] := Sum[b[n, n, k - i] (-1)^i*Binomial[k, i], {i, 0, k}];

%t Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* _Jean-François Alcover_, Apr 30 2020, after _Alois P. Heinz_ *)

%Y Columns k=0-1 give: A000007, A000041 (for n>0).

%Y Main diagonal gives A178682.

%Y Row sums give A326654.

%Y T(2n,n) gives A328158.

%Y Cf. A326656.

%K nonn,tabl

%O 0,5

%A _Alois P. Heinz_, Sep 12 2019

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Last modified September 17 21:55 EDT 2024. Contains 375990 sequences. (Running on oeis4.)