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

1,2

LINKS

R. H. Hardin, Jul 28 2008, Table of n, a(n) for n = 1..25

CROSSREFS

Sequence in context: A015474 A324462 A053601 * A196735 A208438 A122891

Adjacent sequences:  A140987 A140988 A140989 * A140991 A140992 A140993

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jul 28 2008

STATUS

approved

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Last modified September 15 18:22 EDT 2019. Contains 327082 sequences. (Running on oeis4.)