G.f. A(x) satisfies A(F(x)) = x, where F(x) is the g.f. of A251690.

A257084

G.f. A(x) satisfies A(F(x)) = x, where F(x) is the g.f. of A251690.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =17a(4) =80a(5) =407a(6) =2160a(7) =11859a(8) =66754a(9) =383210a(10) =2234921a(11) =13204685a(12) =78870454a(13) =475453371a(14) =2888991879a(15) =17675743626a(16) =108801199823a(17) =673302178725

External references