%I #12 Sep 28 2019 06:08:17
%S 165,1106,7006,11516,12597,14882,16604,21045,23541,39866,42465,43172,
%T 46078,67198,95588,118988,121425,121797,200186,426213,496226,557265,
%U 1183545,1247684,1340241,1379024,2106321,2199716,3236877,3853857,3933045,4313145,4477165,4512375
%N Numbers n such that sigma(n+1)-sigma(n) = -sigma(n)/d(n), where d(n) denotes the number of divisors of n.
%C These are the n at which the divisor sum, sigma(n), is decreasing at a rate equal to the average divisor size, sigma(n)/d(n).
%H Amiram Eldar, <a href="/A066177/b066177.txt">Table of n, a(n) for n = 1..500</a>
%e sigma(165)-sigma(166) = 288-252 = 36 = 288/8 = sigma(165)/d(165).
%t Select[ Range[ 1, 10^5 ], DivisorSigma[ 1, # ]-DivisorSigma[ 1, #+1 ]==DivisorSigma[ 1, # ]/DivisorSigma[ 0, # ] & ]
%Y Cf. A000005 and A000203 (number and sum of divisors).
%K nonn
%O 1,1
%A _Joseph L. Pe_, Dec 14 2001
%E More terms from _Amiram Eldar_, Sep 28 2019