login
A346454
a(n) = [x^n] Product_{k>=1} (1 + n^(k+1)*x^k) / (1 - n^(k+1)*x^k).
1
1, 2, 48, 2592, 223232, 31125000, 6446926080, 1892514990688, 749710432272384, 385769883231774522, 249932498200000000000, 198950665850610546765024, 190770235699567102280073216, 216806274426828873068796386600, 288094786833316639387122903613440
OFFSET
0,2
FORMULA
a(n) ~ 2 * n^(2*n).
MATHEMATICA
Table[SeriesCoefficient[Product[(1 + n^(k + 1)*x^k)/(1 - n^(k + 1)*x^k), {k, 1, n}], {x, 0, n}], {n, 0, 20}]
Table[SeriesCoefficient[2*x + ((1 - n)*QPochhammer[-n, n*x, 1 + n]) / ((1 + n)*QPochhammer[n, n*x, 1 + n]), {x, 0, n}], {n, 0, 20}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Jul 19 2021
STATUS
approved