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 A330739 #7 Jan 11 2020 21:50:04
%S A330739 1,2,1,1,1,2,1,1,1,2,1,2,1,3,2,1,1,3,1,2,3,2,1,1,1,4,1,2,1,4,1,1,1,2,
%T A330739 2,3,1,3,4,2,1,5,1,2,1,2,1,3,1,5,2,2,1,2,2,2,3,3,1,6,1,4,2,1,3,2,1,4,
%U A330739 1,7,1,1,1,4,5,1,2,8,1,3,1,3,1,5,1,3,2,2,1,3,2,2,4,2,3,1,1,6,2,4,1,4,1,1,7
%N A330739 Number of values of k, 1 <= k <= n, with A047994(k) = A047994(n), where A047994 is unitary totient function uphi(n).
%C A330739 Ordinal transform of A047994.
%H A330739 Antti Karttunen, <a href="/A330739/b330739.txt">Table of n, a(n) for n = 1..65537</a>
%o A330739 (PARI)
%o A330739 up_to = 65537;
%o A330739 ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om,invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om,invec[i],(1+pt))); outvec; };
%o A330739 A047994(n) = { my(f=factor(n)~); prod(i=1, #f, (f[1, i]^f[2, i])-1); };
%o A330739 v330739 = ordinal_transform(vector(up_to, n, A047994(n)));
%o A330739 A330739(n) = v330739[n];
%Y A330739 Cf. A047994.
%Y A330739 Cf. also A081373 (ordinal transform of Euler totient function phi), A331177.
%K A330739 nonn
%O A330739 1,2
%A A330739 _Antti Karttunen_, Jan 11 2020