cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A330244 Weird numbers m (A006037) such that sigma(m)/m > sigma(k)/k for all weird numbers k < m, where sigma(m) is the sum of divisors of m (A000203).

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%I A330244 #12 Dec 07 2019 01:53:53
%S A330244 70,10430,1554070,5681270,6365870
%N A330244 Weird numbers m (A006037) such that sigma(m)/m > sigma(k)/k for all weird numbers k < m, where sigma(m) is the sum of divisors of m (A000203).
%C A330244 Benkoski and Erdős asked whether sigma(n)/n can be arbitrarily large for weird number n. Erdős offered $25 for the solution of this question.
%C A330244 No more terms below 10^10.
%D A330244 Richard K. Guy, Unsolved Problems in Number Theory, 3rd Edition, Springer, 2004, Section B2, p. 77.
%H A330244 Stan Benkoski, <a href="http://doi.org/10.2307/2316276">Are All Weird Numbers Even?</a>, Problem E2308, The American Mathematical Monthly, Vol. 79, No. 7 (1972), p. 774.
%H A330244 S. J. Benkoski and P. Erdős, <a href="https://doi.org/10.1090/S0025-5718-1974-0347726-9">On weird and pseudoperfect numbers</a>, Mathematics of Computation, Vol. 28, No. 126 (1974), pp. 617-623, <a href="http://www.renyi.hu/~p_erdos/1974-24.pdf">alternative link</a>, <a href="https://doi.org/10.1090/S0025-5718-1975-0360452-6">corrigendum</a>, ibid., Vol. 29, No. 130 (1975), p. 673.
%H A330244 Paul Erdős, <a href="https://doi.org/10.1007/BFb0063064">Problems and results on combinatorial number theory III</a>, in: M. B. Nathanson (ed.), Number Theory Day, Proceedings of the Conference Held at Rockefeller University, New York 1976, Lecture Notes in Mathematics, Vol 626, Springer, Berlin, Heidelberg, 1977, pp. 43-72. See page 47.
%H A330244 Paul Erdős, <a href="https://doi.org/10.1007/978-1-4612-4086-0_18">Some problems I presented or planned to present in my short talk</a>, in: B. C. Berndt, H. G. Diamond, and A. J. Hildebrand (eds.), Analytic Number Theory, Volume 1, Proceedings of a Conference in Honor of Heini Halberstam, Progress in Mathematics, Vol. 138, Birkhäuser Boston, 1996, pp. 333-335.
%e A330244 The abundancy indices of the terms are sigma(a(n))/a(n) = 2.0571... < 2.0709... < 2.0710... < 2.0716... < 2.0716...
%Y A330244 Cf. A000203, A006037.
%K A330244 nonn,more
%O A330244 1,1
%A A330244 _Amiram Eldar_, Dec 06 2019