A345365 a(n) = (2*n)!*Pi^(-2*n)*PolyLog(2*n, 1)*Clausen(2*n - 1)/2, where Clausen(n) = A160014(n, 1).

1, 4, 16, 64, 1280, 707584, 28672, 59260928, 2874867712, 45773225984, 896021823488, 991382852337664, 143497256501248, 1593799350268461056, 2312797281748024033280, 8277820436597920759808, 11071085050982544965632, 452092922822895257024443973632

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Mathematica

Clausen[n_] := Times @@ (Select[Divisors[n + 1], PrimeQ[# + 1] &] + 1);
a[n_] := (2 n)! PolyLog[2 n, 1] Pi^(-2 n) Clausen[2 n - 1] / 2;
Table[a[n], {n, 1, 18}]

Crossrefs

Cf. A160014.

Sequence in context: A155518 A005401 A002923 * A013149 A175065 A373280

Adjacent sequences: A345362 A345363 A345364 * A345366 A345367 A345368

Keyword

nonn

Author

Peter Luschny, Aug 21 2021

Status

approved