Number of 0..2 arrays of length n with each element differing from at least one neighbor by something other than 1, starting with 0.

A221536

Number of 0..2 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) =2a(2) =4a(3) =10a(4) =22a(5) =54a(6) =134a(7) =334a(8) =822a(9) =2014a(10) =4934a(11) =12110a(12) =29750a(13) =73086a(14) =179494a(15) =440750a(16) =1082262a(17) =2657630a(18) =6526342a(19) =16026766a(20) =39356662a(21) =96646974a(22) =237332966a(23) =582812014a(24) =1431196758a(25) =3514554142a(26) =8630600774a(27) =21193942094a(28) =52045411766a(29) =127806567678

External references