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 A285512 #18 Apr 20 2017 15:15:41
%S A285512 1,1,2,3,2,5,3,5,2,3,2,7,2,3,7,5,3,5,2,11,5,7,5,13,2,5,2,5,2,11,3,5,5,
%T A285512 3,3,7,2,3,7,11,3,11,3,7,7,5,5,13,3,3,5,5,2,5,3,11,5,3,2,13,2,3,5,5,3,
%U A285512 7,2,5,5,19,7,13,5,5
%N A285512 a(n) = smallest integer m>0 such that the positive integers not exceeding m and coprime to n generate the multiplicative group U(Z/nZ).
%C A285512 Denoted G(n) in Burthe (1997).
%C A285512 If A046145(n)>0, then a(n) <= A046145(n).
%C A285512 For all n>=3, a(n) is prime.
%H A285512 Burthe, R. J., Jr. <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa80/aa8042.pdf">Upper bounds for least witnesses and generating sets</a>. Acta Arith. 80:4 (1997), 311-326.
%H A285512 Wikipedia, <a href="https://en.wikipedia.org/wiki/Multiplicative_group_of_integers_modulo_n">Multiplicative group of integers modulo n</a>.
%o A285512 (PARI) { A285512(n) = my(S,s,t); S=Set([Mod(1,n)]); t=1; while( #S!=eulerphi(n), until(n%t,t=nextprime(t+1)); until(#S==s, s=#S; S=setunion(S,Set(S*t))); ); t; }
%Y A285512 Cf. A002997, A046145, A285513, A285514.
%K A285512 nonn
%O A285512 1,3
%A A285512 _Max Alekseyev_ and _Thomas Ordowski_, Apr 20 2017