OFFSET
0,2
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..200
FORMULA
Conjecture: a(n) ~ sqrt(5) * 4^n / (sqrt(Pi) * n^(5/2)). - Vaclav Kotesovec, Feb 05 2022
MAPLE
b:= proc(n) option remember; `if`(n=0, 1,
expand((x^(n^2)+1/x^(n^2))^2*b(n-1)))
end:
a:= n-> coeff(b(n), x, 0):
seq(a(n), n=0..28); # Alois P. Heinz, Jan 28 2022
MATHEMATICA
Table[Coefficient[Product[(x^(k^2) + 1/x^(k^2))^2, {k, 1, n}], x, 0], {n, 0, 30}] (* Vaclav Kotesovec, Feb 05 2022 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 28 2022
STATUS
approved