OFFSET
0,13
COMMENTS
A(n,k) is the k-fold exponential convolution of A000166 with themselves, evaluated at n.
LINKS
FORMULA
E.g.f. of column k: exp(-k*x)/(1 - x)^k.
EXAMPLE
E.g.f. of column k: A_k(x) = 1 + k*x^2/2! + 2*k*x^3/3! + 3*k*(k + 2)*x^4/4! + 4*k*(5*k + 6)*x^5/5! + 5*k*(3*k^2 + 26*k + 24)*x^6/6! + ...
Square array begins:
1, 1, 1, 1, 1, 1, ...
0, 0, 0, 0, 0, 0, ...
0, 1, 2, 3, 4, 5, ...
0, 2, 4, 6, 8, 10, ...
0, 9, 24, 45, 72, 105, ...
0, 44, 128, 252, 416, 620, ...
MATHEMATICA
Table[Function[k, n! SeriesCoefficient[Exp[-k x]/(1 - x)^k, {x, 0, n}]][j - n], {j, 0, 11}, {n, 0, j}] // Flatten
CROSSREFS
Main diagonal gives A295182.
KEYWORD
nonn,tabl
AUTHOR
Ilya Gutkovskiy, Nov 16 2017
STATUS
approved