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 A348414 Numbers with record values of the denominator of the harmonic mean of their divisors. 3
 1, 2, 4, 8, 16, 36, 64, 100, 128, 144, 256, 324, 400, 512, 576, 900, 1296, 1600, 1936, 2304, 3600, 5184, 6400, 8100, 9216, 10404, 11664, 14400, 17424, 20736, 22500, 30276, 32400, 41616, 46656, 57600, 76176, 90000, 108900, 129600, 166464, 202500, 230400, 260100 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The corresponding record values are 1, 3, 7, 15, 31, 91, 127, 217, 255, 403, ... (see the link for more values). LINKS Amiram Eldar, Table of n, a(n) for n = 1..200 Amiram Eldar, Table of n, a(n), A099378(a(n)) for n = 1..200 EXAMPLE The first 4 terms of A099378 are 1, 3, 2 and 7. The record values, 1, 3 and 7, occur at 1, 2 and 4, the first 3 terms of this sequence. MATHEMATICA d[n_] := Denominator[DivisorSigma[0, n]/DivisorSigma[-1, n]]; dm = 0; s = {}; Do[dn = d[n]; If[dn > dm, dm = dn; AppendTo[s, n]], {n, 1, 10^6}]; s CROSSREFS Cf. A099377, A099378. Sequence in context: A085294 A195327 A266544 * A333051 A034340 A034341 Adjacent sequences: A348411 A348412 A348413 * A348415 A348416 A348417 KEYWORD nonn AUTHOR Amiram Eldar, Oct 17 2021 STATUS approved

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Last modified April 18 22:18 EDT 2024. Contains 371782 sequences. (Running on oeis4.)