One quarter the number of nX2 1..4 arrays with no two neighbors of any element equal to each other.

A183354

One quarter the number of nX2 1..4 arrays with no two neighbors of any element equal to each other.

Terms

    a(0) =4a(1) =36a(2) =144a(3) =576a(4) =2304a(5) =9216a(6) =36864a(7) =147456a(8) =589824a(9) =2359296a(10) =9437184a(11) =37748736a(12) =150994944a(13) =603979776a(14) =2415919104a(15) =9663676416a(16) =38654705664a(17) =154618822656a(18) =618475290624

External references