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A264240
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Number of (n+1)X(4+1) arrays of permutations of 0..n*5+4 with each element having directed index change 0,0 1,1 0,-1 -1,1 or 0,-2.
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1
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57, 557, 9005, 119737, 1696877, 23471441, 327315125, 4550623993, 63332634829, 881085142545, 12259302597477, 170566085797129, 2373159477199485, 33018589462835969, 459400051193918037, 6391800733520800057
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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) = 19*a(n-1) -42*a(n-2) -600*a(n-3) +2768*a(n-4) +2064*a(n-5) -29636*a(n-6) +37104*a(n-7) +54432*a(n-8) -121808*a(n-9) +3440*a(n-10) +66048*a(n-11) +320*a(n-12) +115712*a(n-13) -190720*a(n-14) -115456*a(n-15) +246016*a(n-16) +15360*a(n-17) -81920*a(n-18)
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EXAMPLE
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Some solutions for n=4
..0..1..4..3..8....0..1..4..7..8....0..1..4..3..8....0..2..6..3..4
..5..6..7..2..9....5..6..9..2..3....5.10..7..2..9....5.10..1.12..9
.11.13.16.17.14...12.13.16.14.18...12.11..6.13.14...11.15.14..7..8
.15.10.21.12.19...15.10.11.22.19...16.17.21.18.19...17.20.18.19.13
.20.23.22.24.18...20.21.23.17.24...20.15.22.23.24...22.21.16.23.24
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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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