OFFSET
0,3
FORMULA
G.f. satisfies: A(x) = (1-z)*A( z*(1-z)/A(x) ) where z = sqrt(x).
EXAMPLE
A(x) = 1 + x + 3*x^2 + 9*x^3 + 34*x^4 + 131*x^5 + 542*x^6 + 2297*x^7 +...
A(x*(1-x)/A(x^2))*(1-x) = 1 + x^2 + 3*x^4 + 9*x^6 + 34*x^8 + 131*x^10 +...
PROG
(PARI) {a(n)=local(A=1+x); for(n=1, n, A=1/x*serreverse(x/(subst(A, x, x^2+x*O(x^33))/(1-x)))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Oct 21 2008
STATUS
approved