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 A070610 #11 Nov 17 2017 20:33:01
%S A070610 1,2,2,2,3,6,3,3,2,5,6,5,3,10,10,3,5,4,3,8,5,9,10,12,3,8,5,8,5,18,5,4,
%T A070610 13,7,13,4,2,12,8,10,8,19,3,15,6,18,13,7,3,5,18,5,7,21,18,21,7,10,12,
%U A070610 27,4,19,6,2,15,26,3,13,19,26,18,6,2,7,7,8,19,27,7,9,2,13,15,14,13,9
%N A070610 Number of positive integers k such that sigma(k) divides sigma(n).
%H A070610 Antti Karttunen, <a href="/A070610/b070610.txt">Table of n, a(n) for n = 1..16384</a>
%H A070610 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A070610 a(n) = A074754(A000203(n)). - _Antti Karttunen_, Nov 17 2017
%o A070610 (PARI) for(n=1,150,print1(sum(i=1,10*n,if((sigma(n))%(sigma(i)),0,1)),","))
%o A070610 (PARI) A070610(n) = { my(s=sigma(n)); sum(k=1, s, !(s%sigma(k))); }; \\ _Antti Karttunen_, Nov 17 2017
%Y A070610 Cf. A000203, A070242, A071181, A074754.
%K A070610 easy,nonn
%O A070610 1,2
%A A070610 _Benoit Cloitre_, May 13 2002
%E A070610 Offset corrected, name edited by _Antti Karttunen_, Nov 17 2017