cp's OEIS Frontend

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.

A351459 Intersection of A349745 and A351458: numbers k for which k * gcd(sigma(k), A003961(k)) is equal to sigma(k) * gcd(k, A003961(k)) and also k * gcd(sigma(k), A276086(k)) is equal to sigma(k) * gcd(k, A276086(k)).

This page as a plain text file.
%I A351459 #14 Jul 18 2023 21:58:47
%S A351459 1,345080736,459818240,51001180160
%N A351459 Intersection of A349745 and A351458: numbers k for which k * gcd(sigma(k), A003961(k)) is equal to sigma(k) * gcd(k, A003961(k)) and also k * gcd(sigma(k), A276086(k)) is equal to sigma(k) * gcd(k, A276086(k)).
%C A351459 All 3-perfect numbers (A005820) that are even and not multiples of 3 are included in this sequence, including also any hypothetical term of the form 4u+2.
%C A351459 If A323653 is indeed a subsequence of this sequence, then there are no odd perfect numbers. - _Antti Karttunen_, Jul 17 2023
%H A351459 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%H A351459 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A351459 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%Y A351459 Intersection of A349745 and A351458.
%Y A351459 Cf. A323653 (conjectured subsequence, all 23 known terms are present).
%Y A351459 Cf. A000203, A003961, A005820, A276086.
%K A351459 nonn,more
%O A351459 1,2
%A A351459 _Antti Karttunen_, Feb 18 2022