Exponential generating function = (1+x)^(1-x^2).

Terms

a(0) =1a(1) =1a(2) =0a(3) =-6a(4) =-12a(5) =20a(6) =300a(7) =252a(8) =-3024a(9) =-36720a(10) =106560a(11) =110880a(12) =12212640a(13) =-125629920a(14) =1005286464a(15) =-16865735040a(16) =252900345600