A146869 - OEIS

A146869

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1101-1111 pattern in any orientation.

%I #8 Sep 02 2025 12:39:43

%S 1,1,1,1,1,1,9,29,49,117,309,1103,4069,20291,72247,389841,1904157,

%T 13920727,88083783,777496329,5560593885,59069816813

%N Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1101-1111 pattern in any orientation.

%e Maximal 8 X 8 example

%e .0.0.0.0.0.1.1.0

%e .1.0.1.1.0.1.0.0

%e .1.1.1.1.0.1.1.0

%e .0.0.0.0.0.1.1.0

%e .0.1.1.0.0.0.0.0

%e .0.1.1.0.1.1.1.1

%e .0.0.1.0.1.1.0.1

%e .0.1.1.0.0.0.0.0

%K nonn,more

%O 1,7

%A _R. H. Hardin_, Nov 04 2008