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 A324910 #13 Apr 14 2019 17:23:00 %S A324910 1,1,1,3,1,1,1,7,3,1,1,3,1,1,1,15,1,3,1,3,1,1,1,7,3,1,7,3,1,1,1,31,1, %T A324910 1,1,9,1,1,1,7,1,1,1,3,3,1,1,15,3,3,1,3,1,7,1,7,1,1,1,3,1,1,3,63,1,1, %U A324910 1,3,1,1,1,21,1,1,3,3,1,1,1,15,15,1,1,3,1,1,1,7,1,3,1,3,1,1,1,31,1,3,3,9,1,1,1,7,1 %N A324910 Multiplicative with a(p^e) = (2^e)-1. %H A324910 Antti Karttunen, <a href="/A324910/b324910.txt">Table of n, a(n) for n = 1..65537</a> %H A324910 <a href="/index/Eu#epf">Index entries for sequences computed from exponents in factorization of n</a> %F A324910 Multiplicative with a(p^e) = A000225(e). %F A324910 Multiplicative with a(p^e) = A322993(p^e). %F A324910 a(n) = A246674(A156552(n)). %t A324910 Array[Times @@ (2^(FactorInteger[#][[All, -1]]) - 1) &, 105] (* _Michael De Vlieger_, Apr 14 2019 *) %o A324910 (PARI) A324910(n) = factorback(apply(e -> -1+(2^e), factor(n)[,2]~)); %Y A324910 Cf. A000225, A156552, A246674, A322993, A324911. %K A324910 nonn,mult %O A324910 1,4 %A A324910 _Antti Karttunen_, Apr 14 2019