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A220618
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Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor
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1
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8, 317, 9176, 282777, 8608738, 262680517, 8011414792, 244357686173, 7453056468816, 227323314349577, 6933510501158596, 211476640729594693, 6450176661330373022, 196734631145079828705, 6000535646826871036976
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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) = 38*a(n-1) -189*a(n-2) -1434*a(n-3) +6910*a(n-4) -3882*a(n-5) -9380*a(n-6) +9742*a(n-7) -477*a(n-8) -1476*a(n-9) +125*a(n-10)
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EXAMPLE
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Some solutions for n=3 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10)
..0..0..9..9..0....0..0..0..6..4....6..4..7..0..0....0..0..6..4..0
..0..7..0..1..1....0..6..4..9..0....9..3..0..9..0....9..6..4..6..4
..3..0..6..4..0....0..0..0..0..1....0..1..0..0..1....0..1..0..0..0
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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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