A326580 a(n) = (2*n+1)*denominator((2*n+1)*Bernoulli(2*n)).

1, 6, 30, 42, 90, 66, 2730, 30, 510, 798, 2310, 138, 13650, 54, 870, 14322, 5610, 210, 1919190, 78, 13530, 1806, 2070, 282, 324870, 1122, 1590, 43890, 16530, 354, 56786730, 126, 6630, 64722, 690, 4686, 140100870, 150, 2310, 3318, 6210270, 498, 57873270, 174

Offset: 0

Author

Peter Luschny, Jul 17 2019

Keywords

• nonn

Links

• Robert Israel, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A326579, A326578, A326478, A027641/A027642 (Bernoulli).

Programs

Maple

A326580 := n -> (2*n+1)*denom((2*n+1)*bernoulli(2*n)):
seq(A326580(n), n=0..43);

Mathematica

Table[(2n+1)Denominator[(2n+1)BernoulliB[2n]],{n,0,50}] (* Harvey P. Dale, Jul 31 2021 *)

PARI

a(n) = (2*n+1)*denominator((2*n+1)*bernfrac(2*n)); \\ Michel Marcus, Jul 19 2019

Formula

a(n) = A326579(2*n + 1).