1/729 the number of (n+2)X7 0..2 arrays with each 3X3 subblock trace equal to some horizontal or vertical neighbor 3X3 subblock trace.

A186958

1/729 the number of (n+2)X7 0..2 arrays with each 3X3 subblock trace equal to some horizontal or vertical neighbor 3X3 subblock trace.

Terms

    a(0) =201495a(1) =97400287a(2) =22237406277

External references