A357868 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = Sum_{j=0..n} (k*j)!* Stirling2(n,k*j).
1, 1, 0, 1, 1, 0, 1, 0, 3, 0, 1, 0, 2, 13, 0, 1, 0, 0, 6, 75, 0, 1, 0, 0, 6, 38, 541, 0, 1, 0, 0, 0, 36, 270, 4683, 0, 1, 0, 0, 0, 24, 150, 2342, 47293, 0, 1, 0, 0, 0, 0, 240, 1260, 23646, 545835, 0, 1, 0, 0, 0, 0, 120, 1560, 16926, 272918, 7087261, 0, 1, 0, 0, 0, 0, 0, 1800, 8400, 197316, 3543630, 102247563, 0
Offset: 0
Examples
Square array begins: 1, 1, 1, 1, 1, 1, ... 0, 1, 0, 0, 0, 0, ... 0, 3, 2, 0, 0, 0, ... 0, 13, 6, 6, 0, 0, ... 0, 75, 38, 36, 24, 0, ... 0, 541, 270, 150, 240, 120, ...
Crossrefs
Programs
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PARI
T(n, k) = sum(j=0, n, (k*j)!*stirling(n, k*j, 2));
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PARI
T(n, k) = if(k==0, 0^n, n!*polcoef(1/(1-(exp(x+x*O(x^n))-1)^k), n));
Formula
For k > 0, e.g.f. of column k: 1/(1 - (exp(x) - 1)^k).
T(0,k) = 1; T(n,k) = k! * Sum_{j=1..n} binomial(n,j) * Stirling2(j,k) * T(n-j,k).