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.
%I A337993 #25 Feb 01 2024 08:19:36
%S A337993 1,2,4,6,12,24,60,120,360,2520,5040
%N A337993 Numbers k such that L(k) < sigma(k) + k/Pi^2, where L(k) = floor(H(k) + exp(H(k)) * log(H(k))) and H(k) = Sum_{j=1..k} 1/j.
%C A337993 Conjecture: This sequence is finite.
%D A337993 S. Ramanujan, Highly composite numbers, Proc. Lond. Math. Soc. 14 (1915), 347-409; reprinted in Collected Papers, Ed. G. H. Hardy et al., Cambridge 1927; Chelsea, NY, 1962.
%H A337993 J. C. Lagarias, <a href="https://arxiv.org/abs/math/0008177">An elementary problem equivalent to the Riemann hypothesis</a>, arXiv:math/0008177 [math.NT], 2000-2001; Am. Math. Monthly 109 (#6, 2002), 534-543.
%H A337993 Peter Luschny, <a href="/A337993/a337993.jpg">Illustration: Bounds for A057641</a>.
%H A337993 S. Ramanujan, <a href="http://www.imsc.res.in/~rao/ramanujan/CamUnivCpapers/Cpaper15/page15.htm">Highly Composite Numbers</a>, Proc. London Math. Soc. 2, 14, 1915, page 15.
%F A337993 k is a term of this sequence <==> A057640(k) < A000203(k) + k/A002388.
%t A337993 A337993Q[n_] := With[{h = HarmonicNumber[n]}, Floor[h + Exp[h]*Log[h]] < DivisorSigma[1, n] + n/Pi^2];
%t A337993 Select[Range[5040], A337993Q] (* _Paolo Xausa_, Feb 01 2024 *)
%Y A337993 Cf. A000203, A002201, A002388, A004490, A057640, A057641.
%Y A337993 Cf. A001008, A002805.
%K A337993 nonn,more
%O A337993 1,2
%A A337993 _Peter Luschny_, Oct 15 2020