a(n) = denominator(4^(n + 1)*zeta(-n, 1/4)).

Terms

a(0) =1a(1) =6a(2) =1a(3) =60a(4) =1a(5) =126a(6) =1a(7) =120a(8) =1a(9) =66a(10) =1a(11) =16380a(12) =1a(13) =6a(14) =1a(15) =4080a(16) =1a(17) =7182a(18) =1a(19) =3300a(20) =1a(21) =138a(22) =1a(23) =32760a(24) =1a(25) =6a(26) =1a(27) =1740a(28) =1a(29) =42966