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 A319695 #8 Oct 02 2018 17:41:31
%S A319695 0,1,1,1,1,2,1,2,2,2,1,2,1,2,3,3,1,3,1,3,3,2,1,3,2,2,3,3,1,4,1,4,3,2,
%T A319695 3,4,1,2,3,4,1,4,1,3,5,2,1,4,2,3,3,3,1,4,3,5,3,2,1,4,1,2,4,5,3,4,1,3,
%U A319695 3,4,1,6,1,2,5,3,3,4,1,5,4,2,1,5,3,2,3,5,1,6,3,3,3,2,3,5,1,3,5,5,1,4,1,5,7
%N A319695 Number of distinct values obtained when Euler phi (A000010) is applied to proper divisors of n.
%H A319695 Antti Karttunen, <a href="/A319695/b319695.txt">Table of n, a(n) for n = 1..65537</a>
%e A319695 For n = 6, it has three proper divisors: 1, 2, 3, and applying A000010 to these gives 1, 1 and 2, with just two distinct values, thus a(6) = 2.
%o A319695 (PARI) A319695(n) = { my(m=Map(),s,k=0); fordiv(n,d,if((d<n)&&!mapisdefined(m,s=eulerphi(d)), mapput(m,s,s); k++)); (k); };
%Y A319695 Cf. A000010, A319696.
%Y A319695 Cf. also A304793, A305611, A316555, A316556, A319685 for similarly constructed sequences.
%K A319695 nonn
%O A319695 1,6
%A A319695 _Antti Karttunen_, Oct 02 2018