Number of 2nX8 0..3 arrays with values 0..3 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.

A198600

Number of 2nX8 0..3 arrays with values 0..3 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.

Terms

    a(0) =5a(1) =251a(2) =14396a(3) =844228a(4) =49726877a(5) =2934981667a(6) =173328303620

External references