1/6 the number of (n+1)X7 0..2 arrays with every 2X2 subblock containing all three values.

A183600

1/6 the number of (n+1)X7 0..2 arrays with every 2X2 subblock containing all three values.

Terms

    a(0) =10572a(1) =574185a(2) =27768032a(3) =1376627608a(4) =68026656422

External references