Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..3 nX4 array.

A220958

Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..3 nX4 array.

Terms

    a(0) =4a(1) =76a(2) =1769a(3) =33708a(4) =590009a(5) =10032271a(6) =165226050a(7) =2688227848

External references