1/4 the number of nX4 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.
A186163
1/4 the number of nX4 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.
Terms
- a(0) =4a(1) =321a(2) =14364a(3) =751266a(4) =37402872a(5) =1899336597a(6) =95752776009
External references
- oeis: A186163