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A109891
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Least number that requires n steps to reach 0 by repeated application of f: x -> abs(x - reverse(x)).
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0
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0, 1, 10, 16, 14, 15, 13, 1011, 1017, 1037, 1027, 1014, 1013, 1028, 100143, 100135, 100145, 100134, 100103, 100195, 100137, 100227, 100114, 100128, 100194, 100107, 100307, 100277, 100413, 100345, 100429, 100215, 100444, 100237, 100433, 100335
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OFFSET
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0,3
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COMMENTS
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Coincides with A072138 for the first 14 and many later terms.
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LINKS
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EXAMPLE
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f(16) = 61-16 = 45, f(45) = 54-45 = 9, f(9) = 9-9 = 0. For no k < 16 exactly three steps lead to 0, hence a(3) = 16.
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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