This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A345365 #21 Aug 21 2021 11:03:13
%S A345365 1,4,16,64,1280,707584,28672,59260928,2874867712,45773225984,
%T A345365 896021823488,991382852337664,143497256501248,1593799350268461056,
%U A345365 2312797281748024033280,8277820436597920759808,11071085050982544965632,452092922822895257024443973632
%N A345365 a(n) = (2*n)!*Pi^(-2*n)*PolyLog(2*n, 1)*Clausen(2*n - 1)/2, where Clausen(n) = A160014(n, 1).
%t A345365 Clausen[n_] := Times @@ (Select[Divisors[n + 1], PrimeQ[# + 1] &] + 1);
%t A345365 a[n_] := (2 n)! PolyLog[2 n, 1] Pi^(-2 n) Clausen[2 n - 1] / 2;
%t A345365 Table[a[n], {n, 1, 18}]
%Y A345365 Cf. A160014.
%K A345365 nonn
%O A345365 1,2
%A A345365 _Peter Luschny_, Aug 21 2021