login
A140453
Half the number of n X n binary matrices, symmetric under horizontal and vertical reflection, having equal row sums.
1
1, 1, 2, 3, 10, 28, 164, 905, 9826, 103126, 2031252, 43437282, 1622278624, 66141208960, 4579408029576, 385335180349569, 51207103076632066, 8212830157184175946, 2052124795850957537060, 683805150345009276656138
OFFSET
1,3
LINKS
R. H. Hardin, Jul 28 2008, Table of n, a(n) for n = 1..25
CROSSREFS
Sequence in context: A007029 A298083 A099435 * A037169 A058953 A160909
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jul 28 2008
STATUS
approved