Number of 2nX2n 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.
A198246
Number of 2nX2n 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.
Terms
- a(0) =1a(1) =5a(2) =1675a(3) =14520192
External references
- oeis: A198246