a(n) = denominator of Bernoulli(2n)/(2n).

Terms

a(0) =12a(1) =120a(2) =252a(3) =240a(4) =132a(5) =32760a(6) =12a(7) =8160a(8) =14364a(9) =6600a(10) =276a(11) =65520a(12) =12a(13) =3480a(14) =85932a(15) =16320a(16) =12a(17) =69090840a(18) =12a(19) =541200a(20) =75852a(21) =2760a(22) =564a(23) =2227680a(24) =132a(25) =6360a(26) =43092a(27) =6960a(28) =708a(29) =3407203800