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A369437
a(n) = [x^n] Product_{k=1..n} (x^(k^3) + 1 + 1/x^(k^3)).
3
1, 1, 0, 0, 0, 0, 0, 4, 6, 15, 24, 40, 69, 138, 396, 1028, 3062, 8269, 21680, 50955, 115457, 262239, 631393, 1666438, 4558051, 12913587, 35530351, 95825467, 246943968, 628040166, 1607703060, 4228528070, 11485131123, 31616483271, 88141192570, 243487667830
OFFSET
0,8
LINKS
MAPLE
b:= proc(n, i) option remember; `if`(n>(i*(i+1)/2)^2, 0,
`if`(i=0, 1, b(n, i-1)+b(n+i^3, i-1)+b(abs(n-i^3), i-1)))
end:
a:= n-> b(n$2):
seq(a(n), n=0..35); # Alois P. Heinz, Jan 23 2024
MATHEMATICA
Table[Coefficient[Product[(x^(k^3) + 1 + 1/x^(k^3)), {k, 1, n}], x, n], {n, 0, 34}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 23 2024
STATUS
approved