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 A147569 #12 Sep 08 2022 08:45:38
%S A147569 1,3,4,12,28,24,24,72,48,96,120,144,168,192,336,480,360,576,480,720,
%T A147569 720,576,720,1344,1440,1440,1440,1872,1728,1920,1680,2880,2016,1440,
%U A147569 2880,2880,2880,3600,5760,4320,5040,7200,6720,7392,8064,8640,8640,5760,5616
%N A147569 a(n) = sigma(A020492(n)).
%H A147569 Amiram Eldar, <a href="/A147569/b147569.txt">Table of n, a(n) for n = 1..10000</a> (calculated from the b-file at A020492)
%e A147569 a(5) = sigma(A020492(5)) = sigma(12) = 28.
%o A147569 (Magma) [ SumOfDivisors(n): n in [1..3500] | SumOfDivisors(n) mod EulerPhi(n) eq 0 ]; // _Klaus Brockhaus_, Nov 09 2008
%o A147569 (PARI) {for(n=1, 3500, a=sigma(n); if(a%eulerphi(n)==0, print1(a, ",")))} \\ _Klaus Brockhaus_, Nov 09 2008
%Y A147569 Cf. A020492, A023897, A147570.
%K A147569 easy,nonn
%O A147569 1,2
%A A147569 _Enoch Haga_, Nov 07 2008
%E A147569 Edited by _Klaus Brockhaus_, Nov 09 2008