OFFSET
0,3
EXAMPLE
G.f.: 1+x = 1 + 1*x*(1-x)/(1+x) + 2*x^2*(1-x)*(1-2*x)/((1+x)*(1+2*x)) + 10*x^3*(1-x)*(1-2*x)*(1-3*x)/((1+x)*(1+2*x)*(1+3*x)) + 86*x^4*(1-x)*(1-2*x)*(1-3*x)*(1-4*x)/((1+x)*(1+2*x)*(1+3*x)*(1+4*x)) +...
PROG
(PARI) {a(n)=if(n==0, 1, polcoeff(1+x-sum(k=0, n-1, a(k)*x^k*prod(j=1, k, (1-j*x)/(1+j*x+x*O(x^n)))), n))}
for(n=0, 25, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 01 2012
STATUS
approved