Number of 0..4 arrays of length n with each element differing from at least one neighbor by 1 or less, starting with 0.

A221679

Number of 0..4 arrays of length n with each element differing from at least one neighbor by 1 or less, starting with 0.

Terms

    a(0) =0a(1) =2a(2) =5a(3) =26a(4) =100a(5) =418a(6) =1692a(7) =6932a(8) =28288a(9) =115604a(10) =472188a(11) =1929012a(12) =7880012a(13) =32190588a(14) =131500508a(15) =537189116a(16) =2194454252a(17) =8964498844a(18) =36620598988a(19) =149597691420a(20) =611116954220

External references