A309169 a(n) = Product_{d|n} |Stirling1(n,d)|.

1, 1, 2, 66, 24, 7398000, 720, 445824751680, 4762759680, 100329999065856000, 3628800, 1019618790465528595884298768746577920000, 479001600, 97532934291415606872784896000, 5460491900297503751785620701184000, 1567611138605648558776157123803950409816473600000

Offset: 1

Author

Ilya Gutkovskiy, Jul 15 2019

Keywords

• nonn

Crossrefs

Cf. A008275, A058807, A096308, A309171.

Programs

Maple

f:= proc(n) local d; mul(abs(combinat:-stirling1(n,d)),d=numtheory:-divisors(n)) end proc:
map(f, [$1..30]); # Robert Israel, Jul 15 2019

Mathematica

Table[Product[Abs[StirlingS1[n, d]], {d, Divisors[n]}], {n, 1, 16}]

PARI

a(n) = my(d=divisors(n)); prod(k=1, #d, abs(stirling(n, d[k], 1))); \\ Michel Marcus, Jul 16 2019