Number of 3 X n nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal or antidiagonal neighbor (colorings ignoring permutations of colors).

A208303

Number of 3 X n nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal or antidiagonal neighbor (colorings ignoring permutations of colors).

Terms

    a(0) =1a(1) =5a(2) =52a(3) =2906a(4) =373780a(5) =87852626a(6) =33093356640

External references