G.f. satisfies: A(x) = exp( Sum_{n>=1} (Sum_{k=0..2*n} A027907(n,k)^2 * x^k * A(x)^(2*k)) * x^n*A(x)^n/n ), where A027907 is the triangle of trinomial coefficients.
A200475
G.f. satisfies: A(x) = exp( Sum_{n>=1} (Sum_{k=0..2*n} A027907(n,k)^2 * x^k * A(x)^(2*k)) * x^n*A(x)^n/n ), where A027907 is the triangle of trinomial coefficients.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =13a(4) =65a(5) =350a(6) =1981a(7) =11627a(8) =70132a(9) =432090a(10) =2707595a(11) =17202779a(12) =110563543a(13) =717547090a(14) =4695774335a(15) =30952628861a(16) =205318395288
External references
- oeis: A200475