login
A223435
Generalized Petersen graph (8,2) coloring a rectangular array: number of nX3 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
1
144, 1376, 14112, 147520, 1562176, 16693920, 179532768, 1939216640, 21008925952, 228065409888, 2479179661472, 26974655289536, 293678536506304, 3198664399776288, 34848651790913888, 379738193353123456
OFFSET
1,1
COMMENTS
Column 3 of A223440
LINKS
FORMULA
Empirical: 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)
EXAMPLE
Some solutions for n=3
.13.11.13....9.11..9...12..4..5....9.15.13....6..5.13....5..6.14....6..5..6
.15..9.11....1..9..1....4..3..4...15..9.11....7..6..5....6.14.12....5..6..7
.13.11.13....0..1..2....5..4.12....9.15.13....0..7..6...14.12.14....6.14..6
CROSSREFS
Sequence in context: A203819 A222515 A023096 * A169859 A137416 A109117
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 20 2013
STATUS
approved