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A222276
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Number of n X 3 0..5 arrays with no entry increasing mod 6 by 5 rightwards or downwards, starting with upper left zero.
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2
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25, 2205, 194485, 17153945, 1513010465, 133450391205, 11770577485085, 1038187247574145, 91570083319317865, 8076654937439905005, 712376276332499775685, 62832938018547611186345, 5541984245134992804289265
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 92*a(n-1) - 335*a(n-2).
G.f.: 5*x*(5 - 19*x) / (1 - 92*x + 335*x^2).
a(n) = ((46-sqrt(1781))^n*(-801+19*sqrt(1781)) + (46+sqrt(1781))^n*(801+19*sqrt(1781))) / (134*sqrt(1781)).
(End)
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EXAMPLE
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Some solutions for n=3:
..0..0..2....0..3..0....0..3..5....0..0..3....0..3..4....0..0..0....0..3..0
..4..0..3....0..1..3....0..1..2....2..3..1....2..5..5....1..2..4....3..4..0
..2..3..1....2..5..1....2..3..3....4..5..3....3..5..2....3..5..1....0..0..1
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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