Number of n X 1 0..4 arrays with values 0..4 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.
A198662
Number of n X 1 0..4 arrays with values 0..4 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =11a(7) =23a(8) =47a(9) =103a(10) =226a(11) =517a(12) =1194a(13) =2830a(14) =6778a(15) =16498a(16) =40501a(17) =100420a(18) =250513a(19) =628749a(20) =1584525a(21) =4007957a(22) =10164528a(23) =25835883a(24) =65777232a(25) =167694004a(26) =427960360a(27) =1093068944a(28) =2793604179a(29) =7143313914
External references
- oeis: A198662