login
A369387
a(n) is the constant term in expansion of Product_{k=1..n} (x^(2*k-1) + 1 + 1/x^(2*k-1))^2.
0
1, 3, 9, 43, 243, 1539, 10557, 75595, 558117, 4218077, 32466849, 253624579, 2005655781, 16024596491, 129159081787, 1048931938309, 8574963650419, 70507361919587, 582730070295737, 4838280518142269, 40336851095845719, 337541054046113077, 2834101218805540871
OFFSET
0,2
MATHEMATICA
Table[Coefficient[Product[(x^(2 k - 1) + 1 + 1/x^(2 k - 1))^2, {k, 1, n}], x, 0], {n, 0, 22}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 22 2024
STATUS
approved