One quarter the number of nX8 1..4 arrays with no two neighbors of any element equal to each other.

A183360

One quarter the number of nX8 1..4 arrays with no two neighbors of any element equal to each other.

Terms

    a(0) =2916a(1) =147456a(2) =104976a(3) =166464a(4) =331776a(5) =746496a(6) =1806336a(7) =4460544a(8) =9437184a(9) =19501056a(10) =40144896a(11) =84934656a(12) =180633600a(13) =391090176a(14) =840536064a(15) =1816805376a(16) =3893760000a(17) =8387629056a(18) =17960288256a(19) =38654705664a(20) =82833444864a(21) =178259595264

External references