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A355609
Square array T(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of e.g.f. (1 - x)^(-x^k).
5
1, 1, 1, 1, 0, 2, 1, 0, 2, 6, 1, 0, 0, 3, 24, 1, 0, 0, 6, 20, 120, 1, 0, 0, 0, 12, 90, 720, 1, 0, 0, 0, 24, 40, 594, 5040, 1, 0, 0, 0, 0, 60, 540, 4200, 40320, 1, 0, 0, 0, 0, 120, 240, 3528, 34544, 362880, 1, 0, 0, 0, 0, 0, 360, 1260, 25200, 316008, 3628800, 1, 0, 0, 0, 0, 0, 720, 1680, 28224, 263520, 3207240, 39916800
OFFSET
0,6
LINKS
FORMULA
T(0,k) = 1 and T(n,k) = (n-1)! * Sum_{j=k+1..n} j/(j-k) * T(n-j,k)/(n-j)! for n > 0.
T(n,k) = n! * Sum_{j=0..floor(n/(k+1))} |Stirling1(n-k*j,j)|/(n-k*j)!.
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 1, 1, ...
1, 0, 0, 0, 0, 0, 0, ...
2, 2, 0, 0, 0, 0, 0, ...
6, 3, 6, 0, 0, 0, 0, ...
24, 20, 12, 24, 0, 0, 0, ...
120, 90, 40, 60, 120, 0, 0, ...
720, 594, 540, 240, 360, 720, 0, ...
PROG
(PARI) T(n, k) = n!*sum(j=0, n\(k+1), abs(stirling(n-k*j, j, 1))/(n-k*j)!);
CROSSREFS
Columns k=0..4 give A000142, A066166, A353228, A353229, A354624.
Sequence in context: A246117 A295688 A355610 * A266994 A267072 A070677
KEYWORD
nonn,tabl
AUTHOR
Seiichi Manyama, Jul 09 2022
STATUS
approved