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A170810
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Number of permutations of 1..n with all differences of elements separated by distances 1 through 4 being respectively unique.
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0
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1, 2, 4, 12, 40, 116, 200, 444, 760, 2160, 4872, 11932, 29252, 71708, 191356, 536908, 1607592, 5184252, 17331516, 61597568, 228854684, 891958912
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OFFSET
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1,2
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COMMENTS
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(Empirical) Equals A008404 for n<=2m+2, where m is the maximum difference separation 4.
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LINKS
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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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