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 A063500 #22 Dec 19 2021 09:24:08
%S A063500 21,45,63,95,224,135,301,95,189,161,260,115,400,165,476,195,620,145,
%T A063500 644,203,640,285,343,155,728,185,567,155,560,301,860,185,1000,329,
%U A063500 1892,235
%N A063500 a(n) is the least composite solution of phi(k + 6n) = phi(k) + 6n.
%C A063500 Next term (a(37)) exceeds 10^5. - _Matthew Conroy_, Sep 13 2001
%C A063500 Next term (a(37)), if it exists, exceeds 10^7. - _David Wasserman_, Jul 03 2002
%C A063500 If a(37) exists, it is larger than 7.6 * 10^11. - _Jud McCranie_, Aug 29 2013
%C A063500 a(37) > 10^13, if it exists. - _Giovanni Resta_, Feb 25 2020
%F A063500 Smallest values satisfying A000010(a(n)+6n)=A000010(a(n))+6n relation.
%e A063500 n=100, d=600=6n, a(100)=671=11*61, phi(671)=600, phi(671+600)=phi(1271)=(31-1)*(41-1)=600+600=phi(671)+d.
%o A063500 (PARI) for (n=1, 36, a=1; while (isprime(a) || eulerphi(a + 6*n) != eulerphi(a) + 6*n, a++); write("b063500.txt", n, " ", a) ) \\ _Harry J. Smith_, Aug 24 2009
%Y A063500 Cf. A000010, A054904, A054905.
%K A063500 nonn,more
%O A063500 1,1
%A A063500 _Labos Elemer_, Jul 30 2001