OFFSET
0,3
COMMENTS
Generated by a generalization of a recurrence for the Bell numbers (A000110).
Starting with offset 1 = eigensequence of triangle A013609. - Gary W. Adamson, Sep 04 2009
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..81
FORMULA
a(n) = Sum_{k=0..n*(n-1)/2} A126347(n,k)*2^k.
G.f. A(x) satisfies: A(x) = 1 + x*A(2*x/(1 - x))/(1 - x). - Ilya Gutkovskiy, Sep 02 2019
a(n) ~ c * 2^(n*(n-1)/2), where c = A081845 = 4.7684620580627434482997985... - Vaclav Kotesovec, Sep 16 2019
PROG
(PARI) a(n)=if(n==0, 1, sum(k=0, n-1, binomial(n-1, k)*a(k)*2^k))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 01 2007
STATUS
approved