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A223445
4-level binary fanout graph coloring a rectangular array: number of nX4 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 1,3 3,5 3,6 1,4 4,7 4,8 0,2 2,9 9,11 9,12 2,10 10,13 10,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph
1
144, 1616, 20640, 262368, 3364544, 43139520, 553773760, 7110140800, 91312361088, 1172796624128, 15064174682368, 193501020879360, 2485596168674816, 31928841920689152, 410146384220210176, 5268614337966065664
OFFSET
1,1
COMMENTS
Column 4 of A223449
LINKS
FORMULA
Empirical: a(n) = 24*a(n-1) -154*a(n-2) -56*a(n-3) +2992*a(n-4) -6256*a(n-5) -4320*a(n-6) +19040*a(n-7) -6016*a(n-8) -12928*a(n-9) +9600*a(n-10) -1792*a(n-11) for n>12
EXAMPLE
Some solutions for n=3
.10..2.10..2....3..5..3..1...10..2..0..2...14.10..2..9...13.10..2.10
.13.10..2.10....5..3..1..0...13.10..2.10...10.14.10..2...10.13.10.13
.10..2..9..2....3..1..3..1...10..2.10..2...13.10.14.10...14.10..2.10
CROSSREFS
Sequence in context: A109117 A209205 A223594 * A186934 A356731 A368508
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 20 2013
STATUS
approved