1/4 the number of (n+1)X6 0..3 arrays with every 2X2 subblock having at least two equal elements connected horizontally or vertically.

A184149

1/4 the number of (n+1)X6 0..3 arrays with every 2X2 subblock having at least two equal elements connected horizontally or vertically.

Terms

    a(0) =746503a(1) =676507975a(2) =595270788529

External references