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A119240 Least odd number k such that sigma(k)/k >= n. 7


%S 1,945,1018976683725,1853070540093840001956842537745897243375

%N Least odd number k such that sigma(k)/k >= n.

%C These numbers are a subset of the oddly superabundant numbers, A119239. Laatsch mentions a(3). Pettigrew computes a(4) and a(5), the latter being a 123-digit number.

%C Pettigrew (link, Tableau 5, p. 21) gives a(5) as 3^6*5^4*7^3*11^2*13^2*17^2*19*...*277. - _Jeppe Stig Nielsen_, Jul 03 2017

%H Jeppe Stig Nielsen, <a href="/A119240/b119240.txt">Table of n, a(n) for n = 1..5</a>

%H Richard Laatsch, <a href="http://www.jstor.org/stable/2690424">Measuring the abundancy of integers</a>, Mathematics Magazine 59 (2) (1986) 84-92.

%H Walter Nissen, <a href="http://upforthecount.com/math/abundance.html">Abundancy : Some Resources </a>

%H Steve Pettigrew, <a href="http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ55787.pdf">Sur la distribution de nombres spéciaux consécutifs</a>, M.Sc. Thesis, Univ. Laval, 2000.

%Y Cf. A023199 (least number k such that sigma(k)/k >= n).

%K nonn

%O 1,2

%A _T. D. Noe_, May 09 2006

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Last modified May 15 04:03 EDT 2021. Contains 343909 sequences. (Running on oeis4.)