Number of n X n 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.
A198521
Number of n X n 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) =1a(1) =15a(2) =16714a(3) =1084539825
External references
- oeis: A198521