Number of nX4 0..4 arrays with values 0..4 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors.
A198524
Number of nX4 0..4 arrays with values 0..4 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors.
Terms
- a(0) =15a(1) =3660a(2) =1877316a(3) =1084539825a(4) =634586561196
External references
- oeis: A198524