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A229475
Number of defective 4-colorings of an n X 4 0..3 array connected horizontally, antidiagonally and vertically with exactly one mistake, and colors introduced in row-major 0..3 order.
1
6, 248, 3328, 36116, 360912, 3443856, 31875248, 288634368, 2570642816, 22599003712, 196602867456, 1695703281408, 14520402611968, 123579905038336, 1046236716429312, 8817070242804736, 74007384618897408, 618990518429175808
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 24*a(n-1) - 224*a(n-2) + 1096*a(n-3) - 3360*a(n-4) + 6976*a(n-5) - 9744*a(n-6) + 8704*a(n-7) - 4096*a(n-8) for n > 9.
Empirical g.f.: 2*x*(3 + 52*x - 640*x^2 + 2610*x^3 - 6024*x^4 + 7944*x^5 - 2824*x^6 - 4736*x^7 + 10240*x^8) / (1 - 12*x + 40*x^2 - 68*x^3 + 64*x^4)^2. - Colin Barker, Sep 18 2018
EXAMPLE
Some solutions for n=4:
0 1 0 2 0 1 2 3 0 1 2 0 0 1 2 3 0 1 2 3
0 3 1 3 3 0 0 1 2 3 1 3 3 0 1 3 2 3 1 2
1 0 2 0 2 1 3 2 0 2 0 2 2 3 0 2 1 2 1 0
3 1 3 2 0 2 1 0 1 3 2 1 0 2 3 1 3 0 3 2
CROSSREFS
Column 4 of A229479.
Sequence in context: A322559 A229631 A206307 * A281054 A056238 A335158
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 24 2013
STATUS
approved