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 A074230 #12 Jul 24 2016 20:46:15
%S A074230 1,2,3,4,6,8,9,12,16,18,19,24,25,27,29,31,32,36,37,38,47,48,50,53,54,
%T A074230 55,57,58,59,62,64,65,72,74,75,76,81,83,85,87,93,94,96,100,103,106,
%U A074230 108,109,110,111,113,114,115,116,118,121,124,128,130,131,137,139
%N A074230 Numbers n such that A089509(n)=1.
%C A074230 The original name was: Kronecker(7,y) == mu(gcd(7,y)).
%H A074230 Matthew House, <a href="/A074230/b074230.txt">Table of n, a(n) for n = 1..10000</a>
%p A074230 select(t -> numtheory:-jacobi(7,t)=1, [$1..1000]); # _Robert Israel_, Jul 24 2016
%o A074230 (PARI) for (x=1,200, for (y=1,200,if (kronecker(x,y) == moebius(gcd(x,y)),write("km.txt",x,";",y," : ",kronecker(x,y)))))
%Y A074230 Cf. A089509.
%K A074230 nonn
%O A074230 1,2
%A A074230 _Jon Perry_, Sep 17 2002
%E A074230 Name simplified by _Robert Israel_, Jul 24 2016.