A145762 - OEIS

A145762

Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

%I #5 Nov 25 2018 13:03:21

%S 1,1,1,1,2,1,4,1,11,3,36,8,178,27,1006,96,7478,569,70926,4093,898687,

%T 37611,14257237,421080,292647869,6366190,7706237478,123605120,

%U 263373760591,3088656877

%N Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

%K nonn

%O 1,5

%A _R. H. Hardin_, Oct 17 2008