A145776 - OEIS

A145776

Number of n X n binary arrays symmetric about main diagonal with all ones connected only either two adjacent vertically or two adjacent horizontally.

%I #3 Mar 31 2012 12:35:08

%S 1,1,3,8,30,185,1496,16722,271203,6203100,197367854,8915141875,

%T 569403889486,51067273219036,6465618290035839,1155799498602804735,

%U 291067895373206126374,103368821914100007066399

%N Number of n X n binary arrays symmetric about main diagonal with all ones connected only either two adjacent vertically or two adjacent horizontally.

%K nonn

%O 1,3

%A _R. H. Hardin_, Oct 18 2008