A140974 - OEIS

A140974

Number of binary n X n matrices symmetric about both diagonals with rows, considered as binary numbers, in nondecreasing order.

%I #3 Mar 31 2012 12:35:07

%S 1,2,3,4,8,16,43,136,513,2662,15276,134366,1233504,18634052,281749759,

%T 7363023774,187712397424,8557170854702,375321111906249

%N Number of binary n X n matrices symmetric about both diagonals with rows, considered as binary numbers, in nondecreasing order.

%K nonn

%O 0,2

%A _R. H. Hardin_, Jul 27 2008