A191810 G.f. satisfies: A(x) = Sum_{n>=0} x^n*A(x)^binomial(n+3,4).

1, 1, 2, 8, 44, 305, 2521, 24389, 273990, 3569531, 53944055, 944215131, 19065096323, 441174226355, 11609627641798, 344702951590401, 11463058468995522, 424180616752269732, 17366249924363207650, 782666399665891947949

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Example

 G.f.: A(x) = 1 + x + 2*x^2 + 8*x^3 + 44*x^4 + 305*x^5 + 2521*x^6 +...
where the g.f. satisfies:
A(x) = 1 + x*A(x) + x^2*A(x)^5 + x^3*A(x)^15 + x^4*A(x)^35 + x^5*A(x)^70 + x^6*A(x)^126 + x^7*A(x)^210 +...+ x^n*A(x)^(n*(n+1)*(n+2)*(n+3)/4!) +...

Prog

 (PARI) {a(n)=local(A=1+x); for(i=1, n, A=1+sum(m=1, n, x^m*(A+x*O(x^n))^binomial(m+3, 4))); polcoeff(A, n)}

Crossrefs

Cf. A107591, A191809, A191811, A191812.

Sequence in context: A075792 A052897 A137984 * A172109 A005649 A253950

Adjacent sequences: A191807 A191808 A191809 * A191811 A191812 A191813

Keyword

nonn

Author

Paul D. Hanna, Jun 16 2011

Status

approved