A223601 Petersen graph (8,2) coloring a rectangular array: number of 3Xn 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, diagonal or antidiagonal neighbor moves along an edge of this graph.
4096, 1376, 16192, 122608, 1124064, 9902320, 90390720, 827854448, 7658651360, 71165672752, 663933249024, 6209221918896, 58174002355232, 545677201489648, 5122736643803840, 48118345117470448, 452153378054341216
Offset: 1
Keywords
Examples
Some solutions for n=3 ..7.15..9...10.12.14....5..6.14...12.14.12....6..7..0...13.15.13....7..0..8 .13.15.13...14.12.14....7..6..5...12..4.12...15..7..6...13.15..7....1..0..7 .13.11..9...14.12.14...14..6.14...12.14.12...15..7..6....7.15..9....1..0..7
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 13*a(n-1) +3*a(n-2) -437*a(n-3) +544*a(n-4) +3614*a(n-5) -6064*a(n-6) -6480*a(n-7) +14240*a(n-8) -416*a(n-9) -7296*a(n-10) +2304*a(n-11) for n>12
Comments