Number of 2n X 2 0..4 arrays with values 0..4 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors.
A198508
Number of 2n X 2 0..4 arrays with values 0..4 introduced in row major order and each element unequal to exactly two horizontal and vertical neighbors.
Terms
- a(0) =4a(1) =59a(2) =1626a(3) =52065a(4) =1720080a(5) =57202471a(6) =1905005414a(7) =63461666189
External references
- oeis: A198508