A223440 T(n,k)=Generalized Petersen graph (8,2) coloring a rectangular array: number of nXk 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
16, 48, 48, 144, 256, 144, 432, 1376, 1376, 432, 1296, 7424, 14112, 7424, 1296, 3888, 40160, 147520, 147520, 40160, 3888, 11664, 217600, 1562176, 3099264, 1562176, 217600, 11664, 34992, 1180256, 16693920, 67182208, 67182208, 16693920, 1180256
Offset: 1
Examples
Some solutions for n=3 k=4 ..7.15..7..0....1..0..7..0...10..8.14.12....8.14.12.10....9..1..9.11 ..6..7..6..7....2..1..0..7...12.10.12.14...14.12.10..8....1..9.11..9 ..7.15..7.15...10..2..1..0...14..8.14..8....8.14.12.14....9..1..9..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..220
Crossrefs
Column 1 is A188825(n+1)
Formula
Empirical for column k:
k=1: a(n) = 3*a(n-1)
k=2: a(n) = 8*a(n-1) -11*a(n-2) -16*a(n-3)
k=3: a(n) = 15*a(n-1) -18*a(n-2) -310*a(n-3) +167*a(n-4) +475*a(n-5) -244*a(n-6) -100*a(n-7) +48*a(n-8)
k=4: [order 14]
k=5: [order 36]
k=6: [order 75]
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