Number of 0..4 arrays of length n with each element differing from at least one neighbor by 2 or more.

A221520

Number of 0..4 arrays of length n with each element differing from at least one neighbor by 2 or more.

Terms

    a(0) =0a(1) =12a(2) =30a(3) =144a(4) =536a(5) =2172a(6) =8544a(7) =33960a(8) =134480a(9) =533248a(10) =2113456a(11) =8377808a(12) =33207936a(13) =131632288a(14) =521770784a(15) =2068227136a(16) =8198158272a(17) =32496344448a(18) =128810916224a(19) =510588286464

External references