A382947 a(n) = [(x*y)^n] Product_{k>=1} 1 / (1 - x^k - y^k)^k.
1, 2, 16, 78, 426, 1940, 9300, 40530, 177940, 749788, 3137352, 12865488, 52425432, 211336062, 848099898, 3385259588, 13475690578, 53504526568, 212146065506, 840218845230, 3325872415258, 13159945010474, 52064974607244, 205979887425498, 814961759722486
Offset: 0
Keywords
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 0..200
Programs
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Mathematica
Table[SeriesCoefficient[Product[1/(1 - x^k - y^k)^k, {k, 1, n}], {x, 0, n}, {y, 0, n}], {n, 0, 24}]
Formula
a(n) ~ c * 4^n / sqrt(n), where c = 19.59922592... - Vaclav Kotesovec, Apr 11 2025