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A306950
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Numbers m that divide A177754(m) = Sum_{k=1..m} uphi(k), where uphi is the unitary totient function (A047994).
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3
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1, 2, 32, 36, 39, 50, 62, 147, 169, 190, 203, 467, 1035, 1075, 2174, 2475, 27047, 28097, 91087, 181175, 215795, 539654, 580160, 668988, 868879, 2611450, 14359486, 118119399, 1030191204, 1109928219, 2362155122
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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32 is in the sequence since A177754(32) = 384 = 32 * 12 is divisible by 32.
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MATHEMATICA
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uphi[1] = 1; uphi[n_] := Product[{p, e} = pe; p^e-1, {pe, FactorInteger[n]}]; seq={}; s = 0; Do[s = s + uphi[n]; If[Divisible[s, n], AppendTo[seq, n]], {n, 1, 10^6}]; seq (* after Jean-François Alcover at A047994 *)
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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