OFFSET
1,2
COMMENTS
LINKS
Paul D. Hanna, Table of n, a(n) for n = 1..300
FORMULA
a(n) ~ 3^(n + 1/2) / (2*sqrt(Pi*n)). - Vaclav Kotesovec, Jul 10 2018
EXAMPLE
G.f.: A(x) = x + 2*x^2 + 6*x^3 + 17*x^4 + 45*x^5 + 129*x^6 + 357*x^7 + 1026*x^8 + 2908*x^9 + 8380*x^10 + 24068*x^11 + 69670*x^12 + ...
such that Sum_{m>=0} (x^m + 1 + 1/x^m)^m = A(x) + A(1/x) + (infinity)*x^0.
PROG
(PARI) {a(n) = polcoeff( sum(m=1, n, (x^-m + 1 + x^m)^m +x*O(x^n)), n, x)}
for(n=1, 40, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 08 2018
STATUS
approved