A369434 a(n) = [x^(n^2)] Product_{k=1..n} (x^(k^2) + 1 + 1/x^(k^2)).

1, 1, 1, 1, 1, 2, 5, 13, 31, 75, 155, 344, 808, 2019, 5136, 13422, 34720, 91055, 238447, 630753, 1678780, 4502862, 12135507, 32873145, 89324119, 243745113, 667153916, 1832553339, 5048767393, 13950607375, 38649239592, 107345311219, 298820158401, 833680894927

Offset: 0

Author

Ilya Gutkovskiy, Jan 23 2024

Keywords

• nonn

Crossrefs

Cf. A000290, A316706, A350249, A368243.

Programs

Mathematica

Table[Coefficient[Product[(x^(k^2) + 1 + 1/x^(k^2)), {k, 1, n}], x, n^2], {n, 0, 33}]