A147331 - OEIS

A147331

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 00100-00100-11111-00100 pattern in any orientation.

%I #9 Sep 09 2025 07:25:44

%S 1,1,1,1,1,1,5,21,42,179,648,2171,10276,78975,494260

%N Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 00100-00100-11111-00100 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.1.0.0.0

%e .0.0.1.1.1.1.1.0

%e .0.0.0.0.1.0.0.0

%e .0.0.0.1.0.0.0.0

%e .0.1.1.1.1.1.0.0

%e .0.0.0.1.0.0.0.0

%Y Cf. A146846.

%K nonn,more

%O 1,7

%A _R. H. Hardin_