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A140990
Half the number of n X n binary matrices having equal row sums.
1
1, 3, 28, 905, 103126, 43437282, 66141208960, 385335180349569, 8212830157184175946, 683805150345009276656138, 209730232681034628698652412600, 254785524744054762580308183579130562
OFFSET
1,2
LINKS
R. H. Hardin, Jul 28 2008, Table of n, a(n) for n = 1..25
CROSSREFS
Sequence in context: A324462 A053601 A328791 * A196735 A208438 A122891
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 28 2008
STATUS
approved