Number of n X 1 0..4 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling four exactly once.
A269822
Number of n X 1 0..4 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling four exactly once.
Terms
- a(0) =0a(1) =5a(2) =40a(3) =240a(4) =1280a(5) =6400a(6) =30720a(7) =143360a(8) =655360a(9) =2949120a(10) =13107200a(11) =57671680a(12) =251658240a(13) =1090519040a(14) =4697620480a(15) =20132659200a(16) =85899345920a(17) =365072220160
External references
- oeis: A269822