Number of lower triangles of an n X n 0..3 array with no element differing from any of its horizontal or vertical neighbors by more than one.

A194926

Number of lower triangles of an n X n 0..3 array with no element differing from any of its horizontal or vertical neighbors by more than one.

Terms

    a(0) =4a(1) =26a(2) =386a(3) =12474a(4) =882318a(5) =136403494a(6) =46128809462

External references