Number of nX2 0..4 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
A203340
Number of nX2 0..4 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
Terms
- a(0) =1a(1) =5a(2) =25a(3) =95a(4) =425a(5) =2329a(6) =12487a(7) =64444a(8) =337977a(9) =1804892a(10) =9639699a(11) =51382419a(12) =274455029a(13) =1469096024a(14) =7868330298a(15) =42153003025a(16) =225933068001
External references
- oeis: A203340