A108993 a(n) = A108992(n)/(n+1). A(x) = 1/x*series_reversion(x/G108996(x)) where G108996(x) is g.f. of A108996.

1, 1, 3, 19, 205, 3276, 70852, 1953715, 65904057, 2639266228, 122677374326, 6503266277223, 387708627582311, 25700183133977665, 1876381387159576676, 149695388098709302361, 12961535832843534300945

Offset

0,3

Comments

A108992 is the second diagonal of triangle A108990, in which the g.f. of row n, R_n(x), satisfies: [x^k] R_{n+1}(x) = [x^k] (1 + x*R_n(x))^(n+1) for k=0..n+1.

Links

Table of n, a(n) for n=0..16.

Prog

(PARI) {a(n)=local(F=1+x*O(x^n)); for(m=1, n+1, F=(1+x*F)^m); polcoeff(F, n)/(n+1)}

Crossrefs

Cf. A108990, A108991, A108992, A108994, A108995, A108996.

Sequence in context: A301419 A201827 A230321 * A245308 A182956 A052886

Adjacent sequences: A108990 A108991 A108992 * A108994 A108995 A108996

Keyword

nonn

Author

Paul D. Hanna, Jun 15 2005

Status

approved