A140954 Half the number of n X n binary matrices, symmetric under vertical reflection, having equal row sums.

1, 2, 10, 35, 1126, 7592, 1697508, 22458249, 36000614026, 941605438142, 11035829403860196, 572800408273738658, 49759074151291691916640, 5136409738603278958315040, 3340664790391139471267200338312

Offset

1,2

Links

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

Crossrefs

Sequence in context: A146983 A327075 A135963 * A309889 A155894 A317454

Adjacent sequences: A140951 A140952 A140953 * A140955 A140956 A140957

Keyword

nonn

Author

R. H. Hardin, Jul 28 2008

Status

approved