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A367517
a(n) = Product_{1 <= i < j <= n} (i^3 + j^3).
3
1, 9, 8820, 3756261600, 1808353823416358400, 2039434890206782239939575808000, 9701283544768145414379038964290421034844160000, 318565016660642285381616434022976430918222575100233223503872000000
OFFSET
1,2
FORMULA
a(n) ~ c * 2^(n^2 + n/2) * n^(3*n*(n-1)/2 - 9/8) / exp(9*n^2/4 - Pi*n*(n+1) / (2*sqrt(3)) - 3*n/2), where c = 0.1474592465511237361695489773766942970580292170583524962797073759996256...
a(n) = A093883(n) * A203312(n).
MATHEMATICA
Table[Product[Product[i^3 + j^3, {i, 1, j-1}], {j, 2, n}], {n, 1, 10}]
PROG
(Python)
from math import prod
def A367517(n): return prod(i**3+j**3 for i in range(1, n) for j in range(i+1, n+1)) # Chai Wah Wu, Nov 22 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Nov 21 2023
STATUS
approved