A290358 The ninth Euler transform of the sequence with g.f. 1+x.

1, 1, 9, 45, 285, 1575, 9237, 52221, 297633, 1676364, 9425128, 52688379, 293582296, 1629482947, 9015732880, 49727160669, 273504111761, 1500271605182, 8209029290412, 44811239964075, 244069307558722, 1326536980923855, 7195340066129605, 38953817605037254

Offset: 0

Author

Alois P. Heinz, Jul 28 2017

Keywords

• nonn

Comments

Also the number of 9-level rooted trees with n leaves. All n leaves are in level 9.

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..1000
• B. A. Huberman and T. Hogg, Complexity and adaptation, Evolution, games and learning (Los Alamos, N.M., 1985). Phys. D 22 (1986), no. 1-3, 376-384.
• Index entries for sequences related to rooted trees

Crossrefs

Column k=9 of A290353.

Cf. A290357.

Programs

Maple

with(numtheory):
b:= proc(n, k) option remember; `if`(n<2, 1, `if`(k=0, 0, add(
      add(b(d, k-1)*d, d=divisors(j))*b(n-j, k), j=1..n)/n))
    end:
a:= n-> b(n, 9):
seq(a(n), n=0..30);

Mathematica

b[n_, k_]:=b[n, k]=If[n<2, 1, If[k==0, 0, Sum[Sum[b[d, k - 1]*d, {d, Divisors[j]}] b[n - j, k], {j, n}]/n]]; Table[b[n, 9], {n, 0, 30}] (* Indranil Ghosh, Jul 30 2017, after Maple code *)

Formula

G.f.: Product_{j>0} 1/(1-x^j)^A290357(j).