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

Terms

a(0) =1a(1) =-2a(2) =11a(3) =-6a(4) =127a(5) =-10a(6) =221a(7) =-14a(8) =367a(9) =-18a(10) =-1895a(11) =-22a(12) =1447237a(13) =-26a(14) =-57253a(15) =-30a(16) =118526399a(17) =-34a(18) =-5749677193a(19) =-38a(20) =91546283957a(21) =-42a(23) =-46a(25) =-50a(27) =-54a(29) =-58a(31) =-62