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 A324826 #6 Mar 16 2019 21:45:53 %S A324826 1,2,1,3,1,2,1,4,2,3,1,4,1,2,1,5,1,3,1,5,1,3,1,6,2,3,3,4,1,4,1,6,1,3, %T A324826 1,6,1,2,2,7,1,2,1,5,3,3,1,8,2,4,2,5,1,4,1,6,2,2,1,8,1,3,3,7,1,4,1,5, %U A324826 1,3,1,9,1,3,2,4,1,5,1,9,4,3,1,6,2,3,2,7,1,6,1,5,1,3,2,10,1,4,3,7,1,4,1,7,2 %N A324826 Number of divisors d of n such that A323243(d) is either 0 or 1 (mod 4). %H A324826 Antti Karttunen, <a href="/A324826/b324826.txt">Table of n, a(n) for n = 1..10000</a> (based on Hans Havermann's factorization of A156552) %H A324826 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A324826 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A324826 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A324826 a(n) = A000005(n) - A324827(n). %F A324826 a(p) = 1 for all odd primes p. %o A324826 (PARI) A324826(n) = sumdiv(n,d,((A323243(d)%4)<2)); %Y A324826 Cf. A000005, A324825, A324827, A324830, A324831, A324832. %K A324826 nonn %O A324826 1,2 %A A324826 _Antti Karttunen_, Mar 16 2019