One quarter the number of nX6 1..4 arrays with no two neighbors of any element equal to each other.

A183358

One quarter the number of nX6 1..4 arrays with no two neighbors of any element equal to each other.

Terms

    a(0) =324a(1) =9216a(2) =11664a(3) =24336a(4) =57600a(5) =147456a(6) =331776a(7) =746496a(8) =1679616a(9) =3873024a(10) =8856576a(11) =20358144a(12) =46457856a(13) =106502400a(14) =243360000a(15) =557715456a(16) =1275346944a(17) =2921186304a(18) =6682081536a(19) =15300700416a(20) =35007906816a(21) =80147874816a(22) =183403201536

External references