A361805 Expansion of Product_{j=1..n, k=1..n} (1 + x^(k^j)) / (1 - x^(k^j)).
1, 2, 10, 52, 278, 1508, 8262, 45604, 253186, 1412196, 7906866, 44411420, 250124308, 1411963200, 7986664250, 45255888828, 256840959728, 1459686175768, 8306130772008, 47318321533008, 269839722667800, 1540242835509060, 8799238591245006, 50308756959106988
Offset: 0
Keywords
Links
- Vaclav Kotesovec, Table of n, a(n) for n = 0..1000
Crossrefs
Programs
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Mathematica
Table[SeriesCoefficient[Product[Product[(1+x^(k^j))/(1-x^(k^j)), {k, 1, n^(1/j)}], {j, 1, n}], {x, 0, n}], {n, 0, 40}]
Formula
a(n) ~ c * (1 + sqrt(2))^(2*n) / sqrt(n), where c = 0.6431307610999754935775134585988078560575016233514072350040712130921818...