OFFSET
1,1
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..100
FORMULA
a(n) ~ Gamma(1/3) * (9 - 2*Pi*sqrt(3) + 6*log(2)) * 3^(n - 1/2) * n^(n + 7/6) / (2^(3/2) * sqrt(Pi) * exp(n)). - Vaclav Kotesovec, Jan 02 2020
MATHEMATICA
Table[Product[3*k - 1, {k, 1, n+1}] * Sum[(-1)^k/(3*k - 1), {k, 2, n+1}], {n, 1, 20}] (* Vaclav Kotesovec, Jan 02 2020 *)
PROG
(PARI) a(n)={my(s=vector(n+1, k, 3*k-1)); vecprod(s)*sum(k=2, #s, (-1)^k/s[k])} \\ Andrew Howroyd, Jan 01 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Terms a(11) and beyond from Andrew Howroyd, Jan 01 2020
STATUS
approved