Number T(n,m) of ways of 4-coloring an n X m grid so that there is no rectangle with all 4 corners the same color.

A200045

Number T(n,m) of ways of 4-coloring an n X m grid so that there is no rectangle with all 4 corners the same color.

Terms

    a(0) =4a(1) =16a(2) =252a(3) =64a(4) =3912a(5) =228984a(6) =256a(7) =59928a(8) =12870096a(9) =2545607472a(10) =1024a(11) =906912a(12) =696448224a(13) =465659203104a(15) =4096a(16) =13571712a(17) =36376835616a(21) =16384a(22) =201014784

External references