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 A034381 #20 Mar 03 2024 17:17:01 %S A034381 1,2,3,12,30,360,840,10080,60480,907200,3991680,119750400,518918400, %T A034381 14529715200,163459296000,2615348736000,22230464256000, %U A034381 1067062284288000,6758061133824000,304112751022080000,4257578514309120000,112400072777760768000,1175091669949317120000 %N A034381 Number of labeled cyclic groups with n elements. %C A034381 This sequence is strictly increasing, since a(n) = n!/phi(n) > n!/n = (n-1)! >= a(n-1) for n >= 2. - _Jianing Song_, Mar 02 2024 %H A034381 Jianing Song, <a href="/A034381/b034381.txt">Table of n, a(n) for n = 1..450</a> %H A034381 <a href="/index/Gre#groups">Index entries for sequences related to groups</a> %F A034381 a(n) = n!/phi(n). %F A034381 a(n) = A000142(n)/A000010(n) = n*A058161(n). %o A034381 (PARI) a(n) = n! / eulerphi(n) \\ _Jianing Song_, Mar 02 2024 %Y A034381 Cf. A000010, A000142, A034382, A034383, A058161. %K A034381 nonn,easy %O A034381 1,2 %A A034381 _Christian G. Bower_ %E A034381 a(21) onwards from _Jianing Song_, Mar 02 2024