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 A279455 #15 May 19 2017 14:32:45
%S A279455 1,2,3,4,5,6,7,10,11,12,13,14,16,17,19,20,22,23,24,26,27,28,29,30,31,
%T A279455 34,37,38,41,43,44,46,47,48,52,53,54,58,59,61,62,67,68,70,71,73,74,76,
%U A279455 79,80,82,83,86,89,90,92,94,97,101,103,105,106,107,109,110,112,113,116,118
%N A279455 Numbers n such that the number of nonprime divisors of n divides n.
%C A279455 Numbers n such that A033273(n) divides n.
%C A279455 Fixed points of lcm(n, tau(n)-omega(n)), where tau(n) is the number of divisors of n (A000005) and omega(n) is the number of distinct primes dividing n (A001221).
%C A279455 All primes (A000040) are included in the sequence.
%C A279455 All even semiprimes (A100484) are included in the sequence.
%H A279455 G. C. Greubel, <a href="/A279455/b279455.txt">Table of n, a(n) for n = 1..5000</a>
%e A279455 12 is in the sequence because 12 has 6 divisors {1,2,3,4,6,12} out of which 4 are nonprimes {1,4,6,12} and 4 divides 12.
%t A279455 Select[Range[150], Divisible[#1, DivisorSigma[0, #1] - PrimeNu[#1]] & ]
%o A279455 (PARI) isok(n) = denominator(n/sumdiv(n, d, !isprime(d))) == 1; \\ _Michel Marcus_, Dec 17 2016
%Y A279455 Cf. A000005, A000040, A001221, A033950, A033273, A054010, A075592.
%K A279455 nonn,easy
%O A279455 1,2
%A A279455 _Ilya Gutkovskiy_, Dec 12 2016