A319761 a(n) = Product_{i=1..n} i^s(n,i), where s is an unsigned Stirling number of the 1st kind.

1, 1, 2, 24, 5971968, 295334114577121602242226794587320483840

Offset: 0

Author

Jeffrey Shallit, Sep 27 2018

Keywords

• nonn

Examples

			For n = 4 we have a(4) = 1^6*2^11*3^6*4^1 = 5971968.
		

Links

• Paolo Xausa, Table of n, a(n) for n = 0..6

Crossrefs

Cf. A132393, A373796.

Programs

Maple

f:= n -> mul(i^abs(Stirling1(n,i)),i=1..n):
map(f, [$0..6]); # Robert Israel, Sep 27 2018

Mathematica

A319761[n_] := Product[i^Abs[StirlingS1[n, i]], {i, n}];
Array[A319761, 7, 0] (* Paolo Xausa, Jul 10 2024 *)

PARI

a(n) = prod(i=1, n, i^abs(stirling(n, i, 1))); \\ Michel Marcus, Sep 27 2018