A308304 a(n) = (i^n)*Sum_{k=0..n} B_k*|s(n+1,k+1)|*(n+1)^k.

1, 0, 1, 0, 24, 0, 3396, 0, 1706112, 0, 2277172800, 0, 6690143635200, 0, 38006393154105600, 0, 380203596126189158400, 0, 6242084318591496668160000, 0, 159215887013285165806891008000

Offset: 0

Author

René Gy, May 19 2019

Keywords

• nonn

Comments

|s(n,k)| is the unsigned Stirling number of first kind (see A008275), B_k is the Bernoulli number and i^2=-1. All even-indexed terms are positive integers, and the odd-indexed terms are zero. A generating function would be welcomed.

Links

• R. Gy, An aerated triangular array of integers, arXiv: 1902.09309 [math.CO], 2019.

Crossrefs

Cf. A286483.

Programs

PARI

a(n) = (I^n)*sum(k=0, n, bernfrac(k)*abs(stirling(n+1,k+1,1))*(n+1)^k); \\ Michel Marcus, May 19 2019