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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
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
Sequence in context: A085294 A195327 A266544 * A333051 A034340 A034341
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.)