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.

A175874 a(n) = least number such that sigma(a(n)+n)=n*sigma(a(n)).

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%I A175874 #10 Jun 06 2016 08:09:16
%S A175874 14,118,3,2
%N A175874 a(n) = least number such that sigma(a(n)+n)=n*sigma(a(n)).
%C A175874 a(1)= A002961(1).
%C A175874 a(2)= A175876(1), a(3)= A175875(1). - _Zak Seidov_, Jul 07 2013
%C A175874 Is n = 2 the only solution for sigma(n+4)=4*sigma(n)? - _Zak Seidov_, Jul 07 2013
%C A175874 A further solution to sigma(n+4)=4*sigma(n), and the terms a(5) and a(6), if they exist, they are all larger than 3*10^12. - _Giovanni Resta_, Jun 06 2016
%e A175874 sigma(14+1)/sigma(14)=24/24=1, sigma(118+2)/sigma(118)=360/180=2,
%e A175874 sigma(3+3)/sigma(3)=12/4=3, sigma(4+4)/sigma(2)=12/3=4.
%Y A175874 Cf. A000203 sigma(n), A002961 sigma(n) = sigma(n+1).
%Y A175874 Cf. A175875, A175876. - _Zak Seidov_, Jul 07 2013
%K A175874 more,nonn
%O A175874 1,1
%A A175874 _Zak Seidov_, Oct 06 2010