Number of nX4 0..2 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
A203456
Number of nX4 0..2 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
Terms
- a(0) =1a(1) =22a(2) =543a(3) =8837a(4) =143936a(5) =2527020a(6) =44974778a(7) =799146435a(8) =14222292590a(9) =253497958735
External references
- oeis: A203456