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.

A226361 Numbers n such that sigma(n) = sigma(n+1) + sigma(n+2).

This page as a plain text file.
%I A226361 #14 Jul 23 2015 16:17:41
%S A226361 378624,661152,5479092,5526024,7179624,18744216,122321970,168201288,
%T A226361 215676636,778701984,1482154170,1788138780,1974360132,2288979096,
%U A226361 3361923780,4214315484,4757106144,4971510492,6264306144,6884356716,10730488296,11375549304,16851779736
%N A226361 Numbers n such that sigma(n) = sigma(n+1) + sigma(n+2).
%H A226361 Giovanni Resta, <a href="/A226361/b226361.txt">Table of n, a(n) for n = 1..88</a> (terms < 10^13)
%t A226361 nn = 10^7; t = {}; sig0 = 1; sig1 = 3; Do[sig2 = DivisorSigma[1, n + 2]; If[sig0 == sig1 + sig2, AppendTo[t, n]]; sig0 = sig1; sig1 = sig2, {n, nn}]; t (* _T. D. Noe_, Jun 05 2013 *)
%Y A226361 Cf. A000203, A055574, A065900, A073500, A099632.
%K A226361 nonn
%O A226361 1,1
%A A226361 _Alex Ratushnyak_, Jun 05 2013
%E A226361 a(17)-a(23) from _Donovan Johnson_, Jun 05 2013