G.f. satisfies A(x) = 1 + x / (1 + x*A(x))^5.

Terms

a(0) =1a(1) =1a(2) =-5a(3) =10a(4) =20a(5) =-220a(6) =624a(7) =940a(8) =-15220a(9) =52090a(10) =49310a(11) =-1254070a(12) =4951430a(13) =2039640a(14) =-113088840a(15) =505430700a(16) =-42379684a(17) =-10748423405a(18) =53899438385a(19) =-29300595085