1/729 the number of (n+2) X 6 0..2 arrays with each 3 X 3 subblock trace equal to some horizontal or vertical neighbor 3 X 3 subblock trace.

A186957

1/729 the number of (n+2) X 6 0..2 arrays with each 3 X 3 subblock trace equal to some horizontal or vertical neighbor 3 X 3 subblock trace.

Terms

    a(0) =19881a(1) =3277141a(2) =373049827a(3) =47796308777

External references