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 A342542 #19 Mar 19 2021 07:02:07
%S A342542 1,2,3,4,5,7,7,9,15,13,11,33,13,19,105,33,17,91,19,209,469,31,23,641,
%T A342542 1045,37,1627,841,29,4217,31,673,10461,49,29785,10281,37,55,49465,
%U A342542 68769,41,65197,43,12281,529625,67,47,273185,279979,1049661,1049121,52657,53,803647
%N A342542 a(n) = Sum_{k=1..n} phi(gcd(k, n))^(n/gcd(k, n) - 1).
%H A342542 Seiichi Manyama, <a href="/A342542/b342542.txt">Table of n, a(n) for n = 1..5000</a>
%F A342542 a(n) = Sum_{d|n} phi(n/d) * phi(d)^(n/d-1).
%F A342542 If p is prime, a(p) = p.
%t A342542 a[n_] := DivisorSum[n, EulerPhi[n/#] * EulerPhi[#]^(n/#-1) &]; Array[a, 50] (* _Amiram Eldar_, Mar 15 2021 *)
%o A342542 (PARI) a(n) = sum(k=1, n, eulerphi(gcd(k, n))^(n/gcd(k, n)-1));
%o A342542 (PARI) a(n) = sumdiv(n, d, eulerphi(n/d)*eulerphi(d)^(n/d-1));
%Y A342542 Cf. A000010, A029935, A342473, A342540, A342541, A342544.
%K A342542 nonn
%O A342542 1,2
%A A342542 _Seiichi Manyama_, Mar 15 2021