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A103301
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Number of perfect rulers with n segments (n>=0).
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4
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1, 1, 3, 9, 24, 88, 254, 1064, 1644, 3382, 4156, 8022, 26264, 52012, 25434, 8506, 5632, 6224, 12330, 34224, 108854, 103156, 75992, 86560, 69084
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OFFSET
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0,3
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COMMENTS
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For definitions, references and links related to complete rulers see A103294.
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LINKS
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FORMULA
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EXAMPLE
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a(3)=9 counts the perfect rulers with 3 segments, {[0,1,2,4],[0,2,3,4], [0,1,3,4],[0,1,3,5],[0,2,4,5],[0,1,2,5],[0,3,4,5],[0,1,4,6],[0,2,5,6]}.
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CROSSREFS
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KEYWORD
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nonn,hard
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AUTHOR
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EXTENSIONS
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Terms a(19)-a(24) found by exhaustive search by Fabian Schwartau, Yannic Schröder, Lars Wolf, Joerg Schoebel, Feb 23 2021
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STATUS
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approved
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