A124891 L.g.f.: A(x) = log(G124890(x)) where G124890(x) is the g.f. of A124890.

1, 5, 25, 137, 766, 4379, 25355, 148273, 873574, 5177450, 30833342, 184355207, 1105977887, 6653964847, 40131748300, 242567280865, 1468928473132, 8910461020730, 54131814523902, 329299899410062, 2005674943792559

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Formula

a(n) = A124328(2n+2,n+1) for n>=0; thus a(n) is the number of ordered trees with 2(n+1) edges, with thinning limbs and with root of degree n+1.

Example

A(x) = x + 5*x^2/2 + 25*x^3/3 + 137*x^4/4 + 766*x^5/5 + 4379*x^6/6 +...
exp(A(x)) = G124890(x) where
G124890(x) = 1 + x + 3*x^2 + 11*x^3 + 47*x^4 + 216*x^5 + 1047*x^6 +...

Crossrefs

Cf. A124890, A124328, A124889.

Sequence in context: A048370 A272706 A275905 * A358504 A365772 A094094

Adjacent sequences: A124888 A124889 A124890 * A124892 A124893 A124894

Keyword

nonn

Author

Paul D. Hanna, Nov 12 2006

Status

approved