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 A372669 #6 May 10 2024 03:45:27
%S A372669 1,6,16,37,62,121,154,256,339,499,560,884,910,1308,1516,1870,1979,
%T A372669 2889,2756,3776,4023,4814,4795,6716,6330,7908,8301,9946,9520,13406,
%U A372669 11587,14598,15236,17508,17438,22182,19518,24329,24855,29063,26521,35789,30577,37769
%N A372669 a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(n*j*k) / phi(n*k).
%t A372669 Table[Sum[EulerPhi[n*j*k] / EulerPhi[n*k], {j, 1, n}, {k, 1, n}], {n, 1, 50}] (* _Vaclav Kotesovec_, May 10 2024 *)
%o A372669 (PARI) a(n) = sum(j=1, n, sum(k=1, n, eulerphi(n*j*k)/eulerphi(n*k)));
%Y A372669 Cf. A000010, A070639, A372668.
%K A372669 nonn
%O A372669 1,2
%A A372669 _Seiichi Manyama_, May 09 2024