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A189437
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Number of 5 X n array permutations with each element not moving, or moving one space N, SW or SE.
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1
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1, 20, 109, 841, 5680, 40065, 278105, 1940868, 13518605, 94223329, 656569824, 4575509121, 31884910129, 222195588532, 1548403370477, 10790295445561, 75193858910224, 524000231073025, 3651577819301001, 25446593414689700
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 10*a(n-1) -17*a(n-2) -47*a(n-3) +138*a(n-4) -75*a(n-5).
Empirical g.f.: x*(1 - x)*(1 + 11*x - 63*x^2 + 75*x^3) / (1 - 10*x + 17*x^2 + 47*x^3 - 138*x^4 + 75*x^5). - Colin Barker, May 02 2018
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EXAMPLE
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Some solutions for 5 X 3:
..0..4..5....3..4..2....3..1..2....0..1..2....0..4..5....3..4..2....3..4..2
..6..2..1....1..0..5....6..0..8....3..4..8....6..2..1....1..0..8....1..0..8
..9..3..8....6..7.11....4..5.11....6..5.11....9..3.11....6..5.11....6..5.11
..7.13.14....9..8.14....9.10..7...12.13..7...12..8..7...12.13..7....7.13.14
.12.11.10...12.13.10...12.13.14...10..9.14...10.13.14...10..9.14...12..9.10
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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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