OFFSET
0,3
EXAMPLE
G.f.: A(x) = 1 + x + 3*x^2 + 8*x^3 + 26*x^4 + 79*x^5 + 276*x^6 + 936*x^7 +...
where
A(x) = 1/((1 - x*A(x)) * (1 - x^2*A(x^2)^2) * (1 - x^3*A(x^3)^3) *...).
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=1/prod(k=1, n, (1-x^k*subst(A, x, x^k+x*O(x^n))^k))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 31 2012
STATUS
approved