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 A300155 #11 Mar 02 2018 04:06:24
%S A300155 34,38,46,50,54,58,62,105,249,267,268,284,291,292,303,309,316,321,324,
%T A300155 327,332,339,356,363,381,385,388,393,404,411,412,417,428,436,447,452,
%U A300155 453,455,471,484,489,500,501,507,508,519,537,543,573,579,591,595,597
%N A300155 Numbers n for which A243822(n) = A000005(n).
%C A300155 Indices of zeros in A299990, i.e., A010846(n) - 2*A000005(n) = 0.
%C A300155 Composite numbers m have nondivisors k in the cototient such that k | n^e with e > 1. These k appear in row n of A272618 and are enumerated by A243822(n). These nondivisors k are a kind of "regular" number along with divisors d of n; both are listed in row n of A162306 and are together enumerated by A045763(n). Divisors of n are listed in row n of A027750.
%C A300155 This sequence lists numbers that have an equal number of nondivisors k in the cototient of n as divisors d.
%C A300155 The smallest odd term is 105.
%H A300155 Michael De Vlieger, <a href="/A300155/b300155.txt">Table of n, a(n) for n = 1..10000</a>
%e A300155 34 is the first term since it is the smallest number for which A243822(34) = A000005(34). For n = 34, there are 4 divisors {1, 2, 17, 34} and 4 nondivisors 1 <= m <= n such that m | n^e with e > 1: {4, 8, 16, 32}.
%t A300155 Select[Range@ 600, Function[n, Count[Range[n], _?(PowerMod[n, Floor@ Log2@ n, #] == 0 &)] == 2 DivisorSigma[0, n]]]
%Y A300155 Cf. A000005, A010846, A027750, A045763, A162306, A243822, A272618, A299990, A299991, A299992.
%K A300155 nonn
%O A300155 1,1
%A A300155 _Michael De Vlieger_, Feb 26 2018