G.f. A(x) satisfies: A(x*(1+x)^3) = 1 + x.

Terms

a(0) =1a(1) =1a(2) =-3a(3) =15a(4) =-91a(5) =612a(6) =-4389a(7) =32890a(8) =-254475a(9) =2017356a(10) =-16301164a(11) =133767543a(12) =-1111731933a(13) =9338434700a(14) =-79155435870a(15) =676196049060