Number of n X 2 0..3 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
A203840
Number of n X 2 0..3 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.
Terms
- a(0) =1a(1) =4a(2) =16a(3) =50a(4) =184a(5) =810a(6) =3502a(7) =14751a(8) =63204a(9) =274824a(10) =1195748a(11) =5201911a(12) =22685592a(13) =99123373a(14) =433452835a(15) =1896510229a(16) =8302931200a(17) =36367291798a(18) =159341158550a(19) =698313973844
External references
- oeis: A203840