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 A053215 #21 Oct 27 2023 22:00:45
%S A053215 24,312,1440,2160,2688,2640,4320,4464,7644,22932,28314,29040,34560,
%T A053215 37440,51840,56160,65280,100800,115200,114912,120960,120960,138240,
%U A053215 153216,194400,168960,178560,186048,207360,221184,244800,280800,276480
%N A053215 Sum of divisors of those numbers n such that n and n+1 have the same sum of divisors.
%H A053215 Amiram Eldar, <a href="/A053215/b053215.txt">Table of n, a(n) for n = 1..10135</a> (from the b-file at A002961; terms 1..4804 from T. D. Noe)
%F A053215 a(n) = sigma(A002961(n))
%t A053215 Transpose[Select[{DivisorSigma[1,First[#]],DivisorSigma[1,Last[#]]}&/@ Partition[Range[280000],2,1],First[#]==Last[#]&]][[1]] (* _Harvey P. Dale_, May 07 2012 *)
%t A053215 DivisorSigma[1,#]&/@SequencePosition[DivisorSigma[1,Range[280000]],{x_,x_}][[All,1]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 21 2017 *)
%Y A053215 Cf. A000203, A002961, A053249.
%K A053215 nonn
%O A053215 1,1
%A A053215 _Asher Auel_, Jan 11 2000