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 A324830 #6 Mar 16 2019 21:46:14 %S A324830 1,1,2,1,1,3,2,1,3,1,1,4,2,3,3,2,1,4,2,1,4,2,1,5,1,3,4,4,2,4,1,2,3,1, %T A324830 3,5,2,3,4,1,1,6,2,2,5,1,1,7,3,1,3,4,2,6,1,5,4,3,1,5,2,2,6,2,3,6,1,1, %U A324830 3,5,2,7,1,3,4,4,3,6,2,2,5,1,1,8,2,3,4,3,2,7,4,1,3,2,3,8,1,5,5,2,2,5,1,5,7 %N A324830 Number of divisors d of n such that A323243(d) is a multiple of 3. %H A324830 Antti Karttunen, <a href="/A324830/b324830.txt">Table of n, a(n) for n = 1..10000</a> (based on Hans Havermann's factorization of A156552) %H A324830 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A324830 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A324830 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A324830 a(n) = A000005(n) - (A324831(n) + A324832(n)). %F A324830 For all n >= 1, a(A000040(n)) = 2-A000035(n). %o A324830 (PARI) A324830(n) = sumdiv(n,d,(0==(A323243(d))%3)); %Y A324830 Cf. A000005, A156552, A323243, A324831, A324832. %K A324830 nonn %O A324830 1,3 %A A324830 _Antti Karttunen_, Mar 16 2019