Number of n X 4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without move-in move-out left turns.
A221675
Number of n X 4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without move-in move-out left turns.
Terms
- a(0) =4a(1) =139a(2) =5741a(3) =229150a(4) =9062913a(5) =357398390a(6) =14082457465a(7) =554737340774
External references
- oeis: A221675