Number of 2nX6 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.
A198248
Number of 2nX6 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) =2a(1) =40a(2) =1675a(3) =81440a(4) =4059950a(5) =203087097a(6) =10164141586a(7) =508740409496
External references
- oeis: A198248