a(n) = [x^(n^2)] Sum_{m>=0} x^m * (x^(m+1) + i)^m / (1 + i*x^(m+1))^(m+1), for n >= 0.

Terms

a(0) =1a(1) =0a(2) =2a(3) =0a(4) =2a(5) =0a(6) =2a(7) =0a(8) =33284a(9) =0a(10) =2a(11) =0a(12) =883460a(13) =0a(14) =2a(15) =0a(16) =2a(17) =0a(18) =979339580806a(19) =0a(20) =2a(21) =0a(22) =115667460a(23) =0a(24) =2a(25) =0a(26) =2a(27) =0a(28) =799941380a(29) =0