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 A217142 #10 Oct 05 2012 03:05:05
%S A217142 143,52,101,124,104,123,183,156,248,144,208,267,241,365,219,248,312,
%T A217142 306,496,369,288,432,241,543,369,468,482,386,730,444,438,432,496,1220,
%U A217142 624,779,612,801,915,744,723,582,576,1095,864,488,482,641,1086,674,738
%N A217142 Least number m such that phi(m) = phi(m+6n) and m is not divisible by n.
%H A217142 Donovan Johnson, <a href="/A217142/b217142.txt">Table of n, a(n) for n = 2..1000</a>
%o A217142 (PARI) fpr(Nmax, lim) = {for (i=2, Nmax,N = i*6;op = vector(N);f = 0;for (n=1, lim, if (op[n%N+1]+0==op[n%N+1]=eulerphi(n), if ((n-N) % i != 0, f = n-N;break;);););print1(f, ", "););}
%Y A217142 Cf. A000010, A179188, A217068, A217139, A217141.
%K A217142 nonn
%O A217142 2,1
%A A217142 _Michel Marcus_, Sep 27 2012