A139046 Half the number of symmetric n X n binary matrices with the center of gravity of the 1s at the center.

1, 2, 12, 52, 1992, 43472, 8084672, 785972800, 632010796352, 260819509251776, 879345967412550400, 1508148706710022883840, 20993821611583601278837888, 147923394778079541856196475392, 8426633557858801012990635249817088

Offset: 1

Author

R. H. Hardin, Jun 01 2008

Keywords

• nonn

Links

• R. H. Hardin, Jun 01 2008, Table of n, a(n) for n = 1..19

Crossrefs

Cf. A133413.