Number of n X 2 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, vertically or antidiagonally, and no adjacent values equal.

A232155

Number of n X 2 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, vertically or antidiagonally, and no adjacent values equal.

Terms

    a(0) =2a(1) =18a(2) =62a(3) =218a(4) =746a(5) =2600a(6) =9004a(7) =31262a(8) =108492a(9) =376566a(10) =1307146a(11) =4537292a(12) =15750222a(13) =54673186a(14) =189786782a(15) =658806476a(16) =2286917482a(17) =7938591212a(18) =27557292770a(19) =95659868830a(20) =332064969492

External references