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

A184144

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

Terms

    a(0) =43a(1) =17203a(2) =58656073

External references