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 A326043 #5 Jun 04 2019 16:32:53 %S A326043 1,3,4,4,6,12,8,5,7,18,12,16,14,24,24,8,18,21,20,24,32,36,24,20,16,42, %T A326043 14,32,30,72,32,13,48,54,48,28,38,60,56,30,42,96,44,48,42,72,48,32,29, %U A326043 48,72,56,54,42,72,40,80,90,60,96,62,96,56,22,84,144,68,72,96,144,72,35,74,114,64,80,96,168,80,48,31,126 %N A326043 Multiplicative with a(p^e) = floor[((e-1)+sigma(p^e)) / e]. %H A326043 Antti Karttunen, <a href="/A326043/b326043.txt">Table of n, a(n) for n = 1..20000</a> %F A326043 Multiplicative with a(p^e) = floor[(1/e) * (-1 + e + (((p^(1+e)) - 1)/(p-1)))]. %F A326043 a(n) <= A000203(n). %F A326043 a(A048107(n)) = A325973(A048107(n)). %o A326043 (PARI) A326043(n) = if(1==n,n, my(f = factor(n)); prod(i=1, #f~, floor((1/f[i,2]) * ((f[i,2]-1) + (((f[i,1]^(1+f[i,2])) - 1)/(f[i,1]-1)))))); %o A326043 (PARI) A326043(n) = if(1==n,n, my(f = factor(n)); prod(i=1, #f~, floor( ((f[i,2]-1)+sigma(f[i,1]^f[i,2])) / f[i,2]))); %Y A326043 Cf. A000203, A048107, A325973. %K A326043 nonn,mult %O A326043 1,2 %A A326043 _Antti Karttunen_, Jun 04 2019