3-loop graph coloring a rectangular array: number of n X 1 0..6 arrays where 0..6 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
A223240
3-loop graph coloring a rectangular array: number of n X 1 0..6 arrays where 0..6 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
Terms
- a(0) =7a(1) =18a(2) =60a(3) =168a(4) =528a(5) =1536a(6) =4704a(7) =13920a(8) =42144a(9) =125664a(10) =378528a(11) =1132512a(12) =3403680a(13) =10198752a(14) =30620832a(15) =91813344a(16) =275538336a(17) =826418400a(18) =2479648416a(19) =7438158816a(20) =22316049312a(21) =66945002208a(22) =200841298080a(23) =602511311328
External references
- oeis: A223240