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 A336847 #7 Aug 06 2020 23:28:05 %S A336847 0,2,4,12,6,12,10,36,30,28,12,72,16,36,44,120,18,122,22,102,68,52,28, %T A336847 120,54,60,152,150,30,168,36,362,80,76,92,402,40,84,104,312,42,264,46, %U A336847 156,246,108,52,720,132,222,100,216,58,600,84,456,140,124,60,612,66,148,366,1092,140,312,70,258,160,360,72 %N A336847 a(n) = A003973(n) - A336846(n). %H A336847 Antti Karttunen, <a href="/A336847/b336847.txt">Table of n, a(n) for n = 1..16384</a> %H A336847 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %H A336847 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A336847 a(n) = A003973(n) - A336846(n). %o A336847 (PARI) %o A336847 A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; %o A336847 A336847(n) = { my(u=A003961(n),s=sigma(u)); (s-gcd(s, numdiv(n)*u)); }; %Y A336847 Cf. A000005, A000203, A003961, A003973, A336845, A336846, A336848. %K A336847 nonn %O A336847 1,2 %A A336847 _Antti Karttunen_, Aug 06 2020