G.f. A(x) satisfies A(x) = (1 + x)^2 * B(x*A(x)), where B(x) is the g.f. of A001764.

A381938

G.f. A(x) satisfies A(x) = (1 + x)^2 * B(x*A(x)), where B(x) is the g.f. of A001764.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =52a(4) =380a(5) =3066a(6) =26304a(7) =235314a(8) =2170312a(9) =20487963a(10) =196988392a(11) =1922327792a(12) =18990571724a(13) =189548947601

External references