A162034 Number of n X n symmetric binary arrays with rows, considered as binary numbers, in nondecreasing order, and all main diagonal and antidiagonal elements zero

1, 1, 2, 3, 10, 23, 161, 643, 10399, 76674, 2793020, 39088170, 3075920130, 83293952237, 13726688369636, 728989553713898, 246651220048842038, 25910326192430212792, 17788328684183351444219, 3714881265827493365084899

Offset

1,3

Links

R. H. Hardin, Table of n, a(n) for n=1..23

Crossrefs

Sequence in context: A271740 A130002 A320812 * A105286 A295616 A059929

Adjacent sequences: A162031 A162032 A162033 * A162035 A162036 A162037

Keyword

nonn

Author

R. H. Hardin Jun 25 2009

Status

approved