A382959 a(n) = (n!)^2 * [(x*y)^n] Product_{k>=1} (1 + (x^k + y^k)/k!).

1, 0, 0, 6, 8, 130, 342, 2590, 21240, 167730, 1874930, 46128610, 417338462, 5163377570, 542567363366, 3984766703746, 42736508056760, 681324935577810, 127138303030260258, 1011227775808000450, 14280379156264610778, 276342548314653322270, 12566141342987866203746

Offset: 0

Author

Ilya Gutkovskiy, Apr 10 2025

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..100

Crossrefs

Cf. A007837, A108796, A365662.

Programs

Mathematica

Table[(n!)^2 SeriesCoefficient[Product[(1 + (x^k + y^k)/k!), {k, 1, n}], {x, 0, n}, {y, 0, n}], {n, 0, 22}]