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A367956
a(n) = Product_{i=1..n, j=1..n} (i + 3*j).
3
1, 4, 1120, 79833600, 3173289799680000, 123650071173117090201600000, 7337799401269093351612002462597120000000, 951792703318385182295191545713146608287219712000000000000
OFFSET
0,2
FORMULA
a(n) ~ A^(1/3) * 2^(16*n*(n+1)/3 + 13/18) * n^(n^2 - 19/36) / (Pi^(1/3) * Gamma(1/3)^(1/3) * 3^(n*(3*n+4)/2 + 11/36) * exp(3*n^2/2 + 1/36)), where A = A074962 is the Glaisher-Kinkelin constant.
MATHEMATICA
Table[Product[i + 3*j, {i, 1, n}, {j, 1, n}], {n, 0, 10}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Dec 06 2023
STATUS
approved