G.f. A(x) satisfies A(x)^2 = 1 + x + x*A(x)^7.

Terms

a(0) =1a(1) =1a(2) =3a(3) =18a(4) =121a(5) =896a(6) =7028a(7) =57406a(8) =483080a(9) =4159169a(10) =36462855a(11) =324391132a(12) =2921210383a(13) =26576350332a(14) =243901358678