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 A372665 #7 May 09 2024 06:59:13
%S A372665 1,7,14,28,41,63,82,112,137,175,206,252,289,343,386,448,497,567,622,
%T A372665 700,761,847,914,1008,1081,1183,1262,1372,1457,1575,1666,1792,1889,
%U A372665 2023,2126,2268,2377,2527,2642,2800,2921,3087,3214,3388,3521,3703,3842,4032,4177,4375
%N A372665 a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(2*j*k) / phi(j*k).
%H A372665 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TotientFunction.html">Totient Function</a>.
%t A372665 Table[Sum[Sum[EulerPhi[2*j*k]/EulerPhi[j*k], {j, 1, n}], {k, 1, n}], {n, 1, 50}] (* _Vaclav Kotesovec_, May 09 2024 *)
%o A372665 (PARI) a(n) = sum(j=1, n, sum(k=1, n, eulerphi(2*j*k)/eulerphi(j*k)));
%Y A372665 Cf. A000010, A372664.
%K A372665 nonn
%O A372665 1,2
%A A372665 _Seiichi Manyama_, May 09 2024