a(n) = denominator(2^n*Sum_{k=0..n} binomial(n, k)*Bernoulli(k, 1/2)*x^(n-k)).

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =15a(5) =3a(6) =21a(7) =3a(8) =15a(9) =5a(10) =33a(11) =3a(12) =1365a(13) =105a(14) =15a(15) =3a(16) =255a(17) =15a(18) =1995a(19) =105a(20) =1155a(21) =165a(22) =345a(23) =15a(24) =1365a(25) =273a(26) =21a(27) =7a(28) =435a(29) =15