Number of (n+1)X7 0..3 arrays with every 2X2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2X2 subblock traces.

A186920

Number of (n+1)X7 0..3 arrays with every 2X2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2X2 subblock traces.

Terms

    a(0) =1567936a(1) =1613838400a(2) =686342587904

External references