a(n) = ceiling(Bernoulli(2n)/(-4n)).

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =0a(5) =1a(6) =0a(7) =1a(8) =-1a(9) =14a(10) =-140a(11) =1804a(12) =-27413a(13) =487469a(14) =-10026347a(15) =236192434a(16) =-6317862397a(17) =190439655627