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A244052
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Highly regular numbers a(n) defined as positions of records in A010846: a(1) = 1 and a(n) is the least number k > a(n-1) such that A010846(k) > A010846(a(n-1)).
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13
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1, 2, 4, 6, 10, 12, 18, 24, 30, 42, 60, 84, 90, 120, 150, 180, 210, 330, 390, 420, 630, 840, 1050, 1260, 1470, 1680, 1890, 2100, 2310, 2730, 3570, 3990, 4620, 5460, 6930, 8190, 9240, 10920, 11550, 13650, 13860
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OFFSET
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1,2
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COMMENTS
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Analogous to highly divisible numbers (A002182).
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LINKS
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EXAMPLE
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MATHEMATICA
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Function[w, Map[Position[w, #][[1, 1]] &, Union@ Rest@ FoldList[Max, 0, w]]]@ Table[Count[Range@ n, k_ /; PowerMod[n, Floor@ Log2@ n, k] == 0], {n, 10^3}] (* simplest, or *)
f[n_] := If[n == 1, 1, Length@ Function[w, ToExpression@ StringJoin["Module[{n = ", ToString@ n, ", k = 0}, Flatten@ Table[k++, ", Most@ Flatten@ Map[{#, ", "} &, #], "]]"] &@ MapIndexed[Function[p, StringJoin["{", ToString@ Last@ p, ", 0, Log[", ToString@ First@ p, ", n/(", ToString@ InputForm[Times @@ Map[Power @@ # &, Take[w, First@ #2 - 1]]], ")]}"]]@ w[[First@ #2]] &, w]]@Map[{#, ToExpression["p" <> ToString@ PrimePi@ #]} &, FactorInteger[n][[All, 1]]]]; Function[w, Map[Position[w, #][[1, 1]] &, Union@ Rest@ FoldList[Max, 0, w]]]@ Array[f, 14000] (* Michael De Vlieger, Mar 08 2017, more efficient *)
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CROSSREFS
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KEYWORD
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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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