OFFSET
0,6
COMMENTS
The rate of growth of this sequence is surprisingly slow.
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..512
EXAMPLE
G.f.: A(x) = 1 + x + x^2 + x^3 + x^4 + 2*x^5 + x^6 + 3*x^7 + 2*x^8 +...
where
A(x) = 1/((1 - x/A(x)) * (1 - x^2/A(x^2)) * (1 - x^3/A(x^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))))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Sep 28 2011
STATUS
approved