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 A231879 #11 Apr 07 2016 02:38:22
%S A231879 1,6,8,9,10,12,14,15,20,21,22,24,25,26,28,30,32,33,34,35,36,38,39,40,
%T A231879 42,44,46,48,49,50,51,52,54,55,56,57,58,60,62,64,65,66,68,69,70,72,74,
%U A231879 75,76,77,78,80,81,82,84,85,86,87,88,90,91,92,93,94,95,96,98,100,102,104,105,106,108,110,111,112,114,115
%N A231879 Numbers n such that bigomega(n)^2 (cf. A001222) does not divide n.
%C A231879 Contains all semiprimes (A001358) except 4. - _Ivan Neretin_, Apr 05 2016
%H A231879 Ivan Neretin, <a href="/A231879/b231879.txt">Table of n, a(n) for n = 1..10000</a>
%t A231879 Join[{1}, Select[Range[2, 115], ! Divisible[#, PrimeOmega[#]^2] &]] (* _Ivan Neretin_, Apr 05 2016 *)
%o A231879 (PARI) lista(nn) = {print1(1, ", "); for(n=2, nn, if(n % bigomega(n)^2 != 0, print1(n, ", ")));} \\ _Altug Alkan_, Apr 05 2016
%Y A231879 Cf. A001221, A075592, A185307, A001222, A074946, A134334, A231878 (complement).
%K A231879 nonn
%O A231879 1,2
%A A231879 _N. J. A. Sloane_, Nov 17 2013