Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to or 1 greater than any north, west or northwest neighbors modulo 4 and the upper left element equal to 0.
A267405
Number of 4Xn arrays containing n copies of 0..4-1 with every element equal to or 1 greater than any north, west or northwest neighbors modulo 4 and the upper left element equal to 0.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =38a(6) =220a(7) =1182a(8) =5244a(9) =21677a(10) =83121a(11) =317190a(12) =1238406a(13) =5171963a(14) =23008470a(15) =106902558a(16) =502056620a(17) =2337251474a(18) =10681338960a(19) =47951784552a(20) =212639292310a(21) =939284216977
External references
- oeis: A267405