A124549 Derived from a diagonal of rectangular table A124540: a(n) = A124540(n+1,n)/(n+1).

1, 1, 5, 39, 399, 4943, 70846, 1142543, 20355695, 395414964, 8292073877, 186265497096, 4453789285009, 112771923093955, 3010597702761965, 84424863975107571, 2478907364772699611, 75998810193380960765

Offset: 0

Author

Paul D. Hanna, Nov 05 2006

Keywords

• nonn

Comments

In table A124540, the g.f. of row n, R_n(y), simultaneously satisfies: R_n(y) = [ Sum_{k>=0} y^k*R_k(y)^n ]^n for n>=0.

Crossrefs

Cf. A124540, A124548, A124547.

Programs

PARI

a(n)=local(R);R=vector(n+2,r,vector(n+2,c,if(r==1 || c<=2,1,r^(c-2)))); for(i=0,n+1,for(r=0,n+1,R[r+1]=Vec(sum(c=0,n,x^c*Ser(R[c+1])^(r*c)+O(x^(n+2)))))); Vec(Ser(R[n+2])^(n+1)+O(x^(n+2)))[n+1]/(n+1)

Formula

a(n) = A124548(n)/(n+1).