A335750 - OEIS

%I #11 Jun 21 2020 06:01:57

%S 1,1,1,2,4,8,11056,32,231488,5614976,44700416,39773696,242036829184,

%T 1347442688,13896827482112,14116194346606592,126309515939299328,

%U 4968569161351168,1724597636500912693116928,20212640119738990592,68441268157533158650937344,796968953534517505001259008

%N a(n) = numerator(Bernoulli(2*n)*(1/2 - n)! / sqrt(Pi)).

%F a(n) = numerator(-2*n*Zeta(1 - 2*n)*(1/2 - n)! / sqrt(Pi)) for n >= 1.

%e r(n) = 1/2, 1/6, 1/15, 2/63, 4/225, 8/693, 11056/1289925, 32/4455, ...

%p a := n -> bernoulli(2*n)*(1/2 - n)! / sqrt(Pi):

%p seq(numer(simplify(a(n))), n = 0..21);

%Y Cf. A335751 (denominator), A000367/A002445, A004193.

%K nonn,frac

%O 0,4

%A _Peter Luschny_, Jun 20 2020