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 A231877 #9 Apr 25 2017 10:02:12
%S A231877 1,6,10,14,15,18,21,22,26,30,33,34,35,38,39,42,45,46,50,51,54,55,57,
%T A231877 58,60,62,63,65,66,69,70,74,75,77,78,82,84,85,86,87,91,93,94,95,98,99,
%U A231877 102,105,106,110,111,114,115,117,118,119,120,122,123,129,130,132,133,134,135,138,140,141,142,143,145,146,147,150
%N A231877 Numbers n such that omega(n)^2 (cf. A001221) does not divide n.
%H A231877 G. C. Greubel, <a href="/A231877/b231877.txt">Table of n, a(n) for n = 1..1300</a>
%t A231877 Join[{1}, Select[Range[2, 500], Mod[#, PrimeNu[#]^2] != 0 &]] (* _G. C. Greubel_, Apr 24 2017 *)
%Y A231877 Cf. A001221, A075592, A185307, A001222, A074946, A134334, A231876 (complement).
%K A231877 nonn
%O A231877 1,2
%A A231877 _N. J. A. Sloane_, Nov 17 2013