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A330400
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Numbers at which the sum of the iterated unitary totient function (A329153) attains a record.
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3
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1, 2, 3, 4, 5, 8, 9, 16, 17, 29, 32, 41, 45, 53, 64, 73, 83, 85, 101, 113, 125, 128, 137, 153, 187, 197, 233, 257, 389, 401, 512, 577, 641, 677, 685, 703, 773, 901, 929, 977, 1153, 1193, 1493, 1537, 1553, 1657, 1697, 2047, 2048, 2313, 2897, 3089, 3137, 3593, 4001
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OFFSET
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1,2
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COMMENTS
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Analogous to A181659 with the unitary totient function (A047994) instead of the Euler totient function phi (A000010).
The corresponding record values are 0, 1, 3, 6, 10, 16, 24, 39, 55, 70, 85, ... (see the link for more values).
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LINKS
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MATHEMATICA
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uphi[1] = 1; uphi[n_] := Times @@ (-1 + Power @@@ FactorInteger[n]); s[n_] := Plus @@ FixedPointList[uphi, n] - n - 1; seq = {}; smax = -1; Do[s1 = s[n]; If[s1 > smax, smax = s1; AppendTo[seq, n]], {n, 1, 5000}]; seq
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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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