OFFSET
0,12
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..5000
Vaclav Kotesovec, A method of finding the asymptotics of q-series based on the convolution of generating functions, arXiv:1509.08708 [math.CO], Sep 30 2015
FORMULA
G.f.: exp(Sum_{k>=1} x^(9*k)/(k*(1-x^(2*k))^2).
MAPLE
with(numtheory):
a:= proc(n) option remember; local r; `if`(n=0, 1,
add(add(`if`(irem(d-6, 2, 'r')=1, d*r, 0)
, d=divisors(j))*a(n-j), j=1..n)/n)
end:
seq(a(n), n=0..65); # Alois P. Heinz, Oct 17 2015
MATHEMATICA
nmax = 60; CoefficientList[Series[Product[1/(1 - x^(2*k+7))^k, {k, 1, nmax}], {x, 0, nmax}], x]
nmax = 60; CoefficientList[Series[E^Sum[x^(9*k)/(k*(1-x^(2*k))^2), {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Oct 16 2015
STATUS
approved