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 A330400 Numbers at which the sum of the iterated unitary totient function (A329153) attains a record. 3
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 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). LINKS Amiram Eldar, Table of n, a(n) for n = 1..637 (terms below 2*10^9) Amiram Eldar, Table of n, a(n), A329153(a(n)) for n = 1..637 MATHEMATICA 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 CROSSREFS Cf. A047994, A181659, A329153. Sequence in context: A287117 A286431 A015931 * A306044 A263581 A120430 Adjacent sequences:  A330397 A330398 A330399 * A330401 A330402 A330403 KEYWORD nonn AUTHOR Amiram Eldar, Feb 25 2020 STATUS approved

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Last modified July 26 13:40 EDT 2021. Contains 346294 sequences. (Running on oeis4.)