A144059 - OEIS

A144059

Number of n X n binary arrays, symmetric under 180 degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.

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

%S 1,2,7,43,317,4395,85883,3189035,155707292,14992855085,1844750664909,

%T 446183107764907,140966932321586720

%N Number of n X n binary arrays, symmetric under 180 degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.

%K nonn

%O 1,2

%A _R. H. Hardin_, Sep 08 2008