OFFSET
0,2
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
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Nov 12 2006
STATUS
approved