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 A064447 #25 Dec 14 2024 14:41:34
%S A064447 1,2,18,128,2500,15552,705894,8388608,258280326,4000000000,
%T A064447 259374246010,2972033482752,279577021469772,4762288639524864,
%U A064447 233543408203125000,9223372036854775808,778579070010669895696,13115469358432179191808,1874292305362402347591138
%N A064447 a(n) = phi(n^n).
%H A064447 Harry J. Smith, <a href="/A064447/b064447.txt">Table of n, a(n) for n = 1..100</a>
%F A064447 a(n) = A000010(A000312(n)).
%e A064447 For p prime, a(p) = (p^(p-1))*(p-1) = ((phi(p)+1)^phi(p))*phi(p).
%t A064447 a[n_]:=EulerPhi[n^n];lst={};Do[AppendTo[lst, a[n]], {n, 0, 2*4!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Dec 03 2008 *)
%t A064447 Table[EulerPhi[n^n],{n,20}] (* _Harvey P. Dale_, Jun 02 2015 *)
%o A064447 (PARI) a(n) = { eulerphi(n^n) } \\ _Harry J. Smith_, Sep 14 2009
%Y A064447 Cf. A000005, A000010, A000312.
%K A064447 nonn
%O A064447 1,2
%A A064447 _Labos Elemer_, Oct 02 2001