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 A319696 #11 Oct 02 2018 17:41:39
%S A319696 1,1,2,2,2,2,2,3,3,2,2,3,2,2,4,4,2,3,2,4,4,2,2,4,3,2,4,4,2,4,2,5,4,2,
%T A319696 4,5,2,2,4,5,2,4,2,4,6,2,2,5,3,3,4,4,2,4,4,6,4,2,2,5,2,2,5,6,4,4,2,4,
%U A319696 4,4,2,7,2,2,6,4,4,4,2,6,5,2,2,6,4,2,4,6,2,6,4,4,4,2,4,6,2,3,6,6,2,4,2,6,8
%N A319696 Number of distinct values obtained when Euler phi (A000010) is applied to the divisors of n.
%H A319696 Antti Karttunen, <a href="/A319696/b319696.txt">Table of n, a(n) for n = 1..65537</a>
%F A319696 a(n) = A319695(n) + [n (mod 4) != 2], where [ ] is the Iverson bracket, resulting 0 when n = 2 mod 4, and 1 otherwise.
%e A319696 For n = 6, it has four divisors: 1, 2, 3 and 6, and applying A000010 to these gives 1, 1, 2, 2, with just two distinct values, thus a(6) = 2.
%o A319696 (PARI) A319696(n) = { my(m=Map(),s,k=0); fordiv(n,d,if(!mapisdefined(m,s=eulerphi(d)), mapput(m,s,s); k++)); (k); };
%Y A319696 Cf. A000010, A319695.
%Y A319696 Cf. also A184395, A319686.
%K A319696 nonn
%O A319696 1,3
%A A319696 _Antti Karttunen_, Oct 02 2018