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 A128700 #11 Jan 11 2024 20:08:33
%S A128700 1,2,4,8,16,18,36,72,144,288,1800,3600,7200
%N A128700 Highly abundant numbers with an odd divisor sum.
%C A128700 Alaoglu and Erdős showed that 7200 is the largest highly abundant number with all the exponents of its prime factors occurring to powers greater than unity. It follows that the sequence of highly abundant numbers with an odd divisor sum is finite and is bounded above by 7200. Accordingly, this is the complete sequence of such integers.
%H A128700 L. Alaoglu and P. Erdős, <a href="http://www.renyi.hu/~p_erdos/1944-03.pdf">On highly composite and similar numbers</a>, Trans. Amer. Math. Soc., 56 (1944), 448-469.
%H A128700 Wikipedia, <a href="http://en.wikipedia.org/wiki/Highly_abundant_number">Highly Abundant Numbers</a>.
%F A128700 The highly abundant numbers are those integers for which sigma(n) > sigma(m) for all m < n (A002093). This sequence contains those elements of A002093 that have an odd divisor sum.
%e A128700 The fifth highly abundant number with an odd divisor sum is 16. Hence a(5)=16. [Corrected by _N. J. A. Sloane_, Jan 11 2024 at the suggestion of _Harvey P.Dale_.]
%t A128700 hadata1=FoldList[Max,1,Table[DivisorSigma[1,n],{n,2,7200}]]; data1=Flatten[Position[hadata1,#,1,1]&/@Union[hadata1]];Select[data1,OddQ[DivisorSigma[1,# ]] &]
%Y A128700 Cf. A002093, A000203.
%K A128700 easy,full,nice,nonn,fini
%O A128700 1,2
%A A128700 _Ant King_, Mar 28 2007