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A200893
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Triangle read by rows: number of meanders filling out an n X k grid.
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4
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1, 0, 1, 0, 1, 0, 0, 1, 1, 4, 0, 1, 1, 14, 42, 0, 1, 3, 63, 843, 9050, 0, 1, 3, 224, 7506, 342743, 6965359, 0, 1, 8, 1022, 71542, 6971973
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OFFSET
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1,10
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COMMENTS
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The sequence counts the distinct closed paths that visit every cell of an n-by-k rectangular lattice at least once, that never cross any edge between adjacent squares more than once, and that do not self-intersect. Paths related by rotation and/or reflection of the square lattice are not considered distinct.
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LINKS
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FORMULA
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T(n,3) appears to be equal to A090597.
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EXAMPLE
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The 14 solutions for (n,k)=(5,4), 63 solutions for (n,k)=(6,4) and 224 solutions for (n,k)=(7,4) are illustrated in the supporting png files.
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CROSSREFS
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Cf. A200000 (sequence of entries for square grid).
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KEYWORD
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AUTHOR
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STATUS
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approved
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