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 A070320 #12 May 08 2025 02:24:30
%S A070320 1,1,2,2,4,4,6,6,6,6,10,10,12,12,12,12,16,16,18,18,18,18,22,22,22,22,
%T A070320 22,22,28,28,30,30,30,30,30,30,36,36,36,36,40,40,42,42,42,42,46,46,46,
%U A070320 46,46,46,52,52,52,52,52,52,58,58,60,60,60,60,60,60,66,66,66,66,70,70
%N A070320 a(n) = Max( phi(k) : k=1..n ).
%F A070320 a(1) = 1; for n >= 2, a(n) = A007917(n)-1.
%t A070320 Module[{nn=80,ep},ep=EulerPhi[Range[nn]];Table[Max[Take[ep,n]],{n,nn}]] (* _Harvey P. Dale_, Jul 23 2023 *)
%t A070320 a[n_] := NextPrime[n + 1, -1] - 1; a[1] = 1; Array[a, 100] (* _Amiram Eldar_, May 08 2025 *)
%o A070320 (PARI) a(n) = if(n == 1, 1, precprime(n) - 1); \\ _Amiram Eldar_, May 08 2025
%Y A070320 Cf. A007917.
%K A070320 easy,nonn
%O A070320 1,3
%A A070320 _Benoit Cloitre_, May 11 2002