OFFSET
0,4
COMMENTS
Inspired by Peter Bala's formula in A229046.
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..400
EXAMPLE
G.f.: A(x) = 1 + x + x^2 + 4*x^3 + 13*x^4 + 51*x^5 + 234*x^6 +...
where
A(x) = 1 + x/((1+x)^2*(1-2*x)) + x^2/((1+x)^4*(1-4*x)) + x^3/((1+x)^6*(1-6*x))+ x^4/((1+x)^8*(1-8*x))+ x^5/((1+x)^10*(1-10*x)) + x^6/((1+x)^12*(1-12*x)) +...
PROG
(PARI) {a(n)=polcoeff( sum(m=0, n, x^m/((1+x)^(2*m)*(1 - 2*m*x) +x*O(x^n))), n)}
for(n=0, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 15 2014
STATUS
approved