Number of nX4 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.
A221251
Number of nX4 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.
Terms
- a(0) =4a(1) =81a(2) =2116a(3) =58081a(4) =1612900a(5) =44903401a(6) =1250753956a(7) =34842328921a(8) =970622980804
External references
- oeis: A221251