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 A091439 #19 Feb 16 2025 08:32:52
%S A091439 1,2,6,210,30030,223092870,13082761331670030,
%T A091439 3217644767340672907899084554130,
%U A091439 1492182350939279320058875736615841068547583863326864530410,16516447045902521732188973253623425320896207954043566485360902980990824644545340710198976591011245999110
%N A091439 Least k such that k/phi(k) >= n, where phi is Euler's totient function.
%H A091439 Max Alekseyev, <a href="/A091439/b091439.txt">Table of n, a(n) for n = 1..15</a>
%H A091439 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TotientFunction.html">Totient Function</a>
%F A091439 a(n) = A002110(A256968(n)). - _Michel Marcus_, Oct 07 2019
%t A091439 Table[prod=1; i=0; While[prod<n, i++; prod=prod/(1-1/Prime[i])]; Times@@Prime[Range[i]], {n, 1, 9}]
%o A091439 (PARI) a(n) = my(p=1, i=0); while(p<n, i++; p = p/(1-1/prime(i))); prod(k=1, i, prime(k)); \\ _Michel Marcus_, Oct 07 2019
%Y A091439 Subsequence of A002110.
%Y A091439 Cf. A091456 (n * phi(k) < k), A256968, A266269, A266276.
%K A091439 easy,nonn
%O A091439 1,2
%A A091439 _T. D. Noe_, Jan 09 2004