1/25 the number of (n+1) X 4 0..4 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements.

A203651

1/25 the number of (n+1) X 4 0..4 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements.

Terms

    a(0) =729a(1) =28057a(2) =1116249a(3) =44577561a(4) =1780968921a(5) =71156938905

External references