G.f. A(x) satisfies A(x)^7 = A(x^7) + 7*A(x^8).

Terms

a(0) =1a(1) =1a(2) =-3a(3) =13a(4) =-65a(5) =351a(6) =-1989a(7) =11650a(8) =-69900a(9) =427168a(10) =-2648444a(11) =16612986a(12) =-105215708a(13) =671762688a(14) =-4318480068a(15) =27926208102a(16) =-181520595372