a(n) = Bernoulli(2*n) * (2*n + 1)!.

A001332

a(n) = Bernoulli(2*n) * (2*n + 1)!.

Terms

    a(0) =1a(1) =1a(2) =-4a(3) =120a(4) =-12096a(5) =3024000a(6) =-1576143360

External references