Number of 2nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to exactly one horizontal or vertical neighbor.

A198529

Number of 2nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to exactly one horizontal or vertical neighbor.

Terms

    a(0) =12a(1) =206a(2) =3838a(3) =74582a(4) =1481214a(5) =29737425a(6) =600187403a(7) =12144602583a(8) =246046084954

External references