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 A246913 #12 Sep 08 2022 08:46:09 %S A246913 831376,3944688,16956576,17843616,22591296,25371360,27870976,51878736, %T A246913 58877280,64641984,142990848,164898720,172821456,181821024,204330672, %U A246913 276371200,281613024,301571424,319848480,326207700,342237456,346502520,389165568,389450880,392110992 %N A246913 Numbers n such that sigma(n+sigma(n)) = 6*sigma(n). %C A246913 a(310) > 10^11. - _Hiroaki Yamanouchi_, Sep 11 2015 %H A246913 Hiroaki Yamanouchi, <a href="/A246913/b246913.txt">Table of n, a(n) for n = 1..309</a> %e A246913 Number 831376 (with sigma(831376) = 1985984) is in sequence because sigma(831376+sigma(831376)) = sigma(2817360) = 11915904 = 6*1985984. %o A246913 (Magma) [n:n in[1..10^7] | SumOfDivisors(n+SumOfDivisors(n))eq 6*SumOfDivisors(n)] %o A246913 (PARI) %o A246913 for(n=1,10^7,if(sigma(n+sigma(n))==6*sigma(n),print1(n,", "))) \\ _Derek Orr_, Sep 07 2014 %Y A246913 Cf. A000203, A246456, A246909-A246912, A246914. %K A246913 nonn %O A246913 1,1 %A A246913 _Jaroslav Krizek_, Sep 07 2014 %E A246913 a(5)-a(25) from _Hiroaki Yamanouchi_, Sep 11 2015