G.f. satisfies: A(x) = C(2x)^2 * A(x^3*C(2x)^4), where C(x) is the g.f. of the Catalan numbers (A000108).
A120915
G.f. satisfies: A(x) = C(2x)^2 * A(x^3*C(2x)^4), where C(x) is the g.f. of the Catalan numbers (A000108).
Terms
- a(0) =1a(1) =4a(2) =20a(3) =116a(4) =720a(5) =4656a(6) =30996a(7) =210896a(8) =1459536a(9) =10239796a(10) =72651184a(11) =520328112a(12) =3756512912a(13) =27307671040a(14) =199705789248
External references
- oeis: A120915