a(n) = denominator(4^n * n! * [x^n] sqrt(x / (e^x - 1))).

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =5a(5) =3a(6) =21a(7) =3a(8) =45a(9) =5a(10) =11a(11) =1a(12) =91a(13) =35a(14) =45a(15) =3a(16) =17a(17) =3a(18) =1995a(19) =21a(20) =3465a(21) =165a(22) =115a(23) =45a(24) =2925a(25) =819a(26) =189a(27) =7a(28) =145a(29) =5