OFFSET
0,4
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..300
EXAMPLE
G.f.: A(x) = 1 + x + x^2 + 2*x^3 + 3*x^4 + 9*x^5 + 21*x^6 + 76*x^7 + 241*x^8 + 962*x^9 + 3687*x^10 + 15930*x^11 + 68993*x^12 + 320025*x^13 + 1511977*x^14 + ...
such that
1 = 1/A(x) + x*(1+x)/A(x)^2 + x^2*(1+2*x)^2/A(x)^3 + x^3*(1+3*x)^3/A(x)^4 + x^4*(1+4*x)^4/A(x)^5 + x^5*(1+5*x)^5/A(x)^6 + x^6*(1+6*x)^6/A(x)^7 + ...
PROG
(PARI) {a(n) = my(A=[1]); for(i=1, n, A=concat(A, 0);
A[#A] = polcoeff( sum(n=0, #A, x^n*(1+n*x)^n/Ser(A)^(n+1)), #A-1); ); A[n+1]}
for(n=0, 40, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 19 2019
STATUS
approved