OFFSET
0,3
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..50
FORMULA
a(n) = A333361(n, 2*n). - Andrew Howroyd, Mar 16 2020
PROG
(PARI) a(n)={polcoef(G(2*n, x + O(x*x^(n))), n)} \\ Needs G from A333361. - Andrew Howroyd, Mar 16 2020
(PARI) \\ faster, also needs G from A333361.
EulerT(v)={Vec(exp(x*Ser(dirmul(v, vector(#v, n, 1/n))))-1, -#v)}
InvEulerMT(u)={my(n=#u, p=log(1+x*Ser(u)), vars=variables(p)); Vec(sum(i=1, n, moebius(i)*substvec(p + O(x*x^(n\i)), vars, apply(v->v^i, vars))/i))}
seq(n)={concat([1], EulerT(Vec(-1 + vecsum(InvEulerMT(vector(n+1, k, G(k, y + O(y*y^n))))))))} \\ Andrew Howroyd, Mar 16 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Jan 26 2000
EXTENSIONS
a(16)-a(25) from Max Alekseyev, Jun 21 2011
STATUS
approved