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

A221538

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

Terms

    a(0) =0a(1) =4a(2) =14a(3) =68a(4) =303a(5) =1386a(6) =6311a(7) =28762a(8) =131012a(9) =596784a(10) =2718469a(11) =12383368a(12) =56409683a(13) =256961576a(14) =1170529586a(15) =5332078812a(16) =24289062227a(17) =110643256974a(18) =504010005519

External references