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 A063444 #9 Aug 19 2016 00:43:06
%S A063444 3,12,13,15,121,35,86,64,37,99,726,72,158,196,61,96,4931,73,7639,175,
%T A063444 343,267,2302,104,250,676,162,637,3481,154,21142,192,2178,411,5041,
%U A063444 814,446,1145,157,164,6971,1348,14878,1334,542,2115,22090,193,2842,2200
%N A063444 Smallest number such that GCD of EulerPhi of 2 consecutive integer equals 2n.
%H A063444 Harry J. Smith, <a href="/A063444/b063444.txt">Table of n, a(n) for n=1,...,350</a>
%F A063444 Min{x; GCD[Phi[x+1], Phi[x]]=2n}=Min{x; A058515[x]=2n}
%e A063444 n = 10, a(10) = 99, Phi(99) = 60, Phi(100) = 40, GCD[60,40] = 2n = 20.
%o A063444 (PARI) { for (n=1, 350, x=1; while (gcd(eulerphi(x+1), eulerphi(x)) != 2*n, x++); write("b063444.txt", n, " ", x) ) } \\ _Harry J. Smith_, Aug 21 2009
%Y A063444 A000010, A058515.
%K A063444 nonn
%O A063444 1,1
%A A063444 _Labos Elemer_, Jul 24 2001