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A356724
Number of n X n tables where each row represents a permutation of { 1, 2, ..., n } and the column sums are equal, up to permutation of rows.
6
1, 1, 2, 114, 60024, 1951262760, 4029043460476320, 823357371521186302202640
OFFSET
1,3
FORMULA
a(n) = the coefficient of (x1*...*xn)^(n*(n-1)/2) in 1/Product(1 - x1^(n-1)*x2^(n-2)*...*xn^0), where the product is taken over all permutations of the variables x1, ..., xn.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Max Alekseyev, Aug 25 2022
STATUS
approved