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

Terms

a(0) =1a(1) =6a(2) =30a(3) =42a(4) =90a(5) =66a(6) =2730a(7) =30a(8) =510a(9) =798a(10) =2310a(11) =138a(12) =13650a(13) =54a(14) =870a(15) =14322a(16) =5610a(17) =210a(18) =1919190a(19) =78a(20) =13530a(21) =1806a(22) =2070a(23) =282a(24) =324870a(25) =1122a(26) =1590a(27) =43890a(28) =16530a(29) =354