OFFSET
0,4
EXAMPLE
1/(1-x) = 1 + x*(1-x)/(1-x)
+ x^2*(1 - 2^2*x + x^2)/(1-x)^2
+ 3*x^3*(1 - 3^2*x + 3^2*x^2 - x^3)/(1-x)^3
+ 23*x^4*(1 - 4^2*x + 6^2*x^2 - 4^2*x^3 + x^4)/(1-x)^4
+ 319*x^5*(1 - 5^2*x + 10^2*x^2 - 10^2*x^3 + 5^2*x^4 - x^5)/(1-x)^5
+ 6857*x^6*(1 - 6^2*x + 15^2*x^2 - 20^2*x^3 + 15^2*x^4 - 6^2*x^5 + x^6)/(1-x)^6 +...
PROG
(PARI)
{a(n)=if(n==0, 1, 1-polcoeff(sum(k=0, n-1, a(k)*x^k*sum(j=0, k, binomial(k, j)^2*(-x)^j)/(1-x+x*O(x^n))^k), n))}
for(n=0, 20, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 31 2013
STATUS
approved