1/24 the number of (n+1)X7 0..3 arrays with every 2X2 subblock containing exactly three distinct values.

A183591

1/24 the number of (n+1)X7 0..3 arrays with every 2X2 subblock containing exactly three distinct values.

Terms

    a(0) =417152a(1) =293504588a(2) =202888369698

External references