OFFSET
0,4
EXAMPLE
G.f.: A(x) = 1 + x + x^2 + 4*x^3 + 13*x^4 + 54*x^5 + 227*x^6 + 1019*x^7 +...
where g.f. A = A(x) satisfies:
A(x) = 1 + x*(A-x) + x^2*(A-x)*(A^2-x^2) + x^3*(A-x)*(A^2-x^2)*(A^3-x^3) + x^4*(A-x)*(A^2-x^2)*(A^3-x^3)*(A^4-x^4) + x^5*(A-x)*(A^2-x^2)*(A^3-x^3)*(A^4-x^4)*(A^5-x^5) +...
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=1+sum(m=1, n, x^m*prod(k=1, m, A^k-x^k +x*O(x^n)))); polcoeff(A, n)}
for(n=0, 40, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Sep 15 2013
STATUS
approved