A367517 - OEIS

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A367517

a(n) = Product_{1 <= i < j <= n} (i^3 + j^3).

1, 9, 8820, 3756261600, 1808353823416358400, 2039434890206782239939575808000, 9701283544768145414379038964290421034844160000, 318565016660642285381616434022976430918222575100233223503872000000

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..8.

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

Cf. A203475, A324426.

Cf. A093883, A203312.

Sequence in context: A053975 A191961 A188965 * A327897 A249837 A240091

Adjacent sequences: A367514 A367515 A367516 * A367518 A367519 A367520

KEYWORD

nonn

AUTHOR

Vaclav Kotesovec, Nov 21 2023

STATUS

approved