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 A143407 #6 Mar 19 2016 14:38:29 %S A143407 2,24,240,504,480,264,65520,16320,28728,13200,552,131040,6960,171864, %T A143407 32640,138181680,1082400,151704,5520,1128,4455360,12720,86184,13920, %U A143407 1416,6814407600,65280,776664,18744,20174525280,39816,36801600,1992 %N A143407 Largest number k such that the reduced totient function psi(k) = A002174(n). %C A143407 For each of the values in A002174, there are only a finite number of numbers k such that psi(k)=A002174(n). This sequence gives the largest such k. Sequence A002396 gives the least k. The number of such k is given in A143408. When A002174(n) is twice a Sophie Germain prime, then a(n) is particularly small. %H A143407 T. D. Noe, <a href="/A143407/b143407.txt">Table of n, a(n) for n=1..1000</a> %F A143407 a(n) = A006863(A002174(n)/2) for n>1. %Y A143407 Cf. A002322 (reduced totient function), A002174, A002396, A143408. %K A143407 nonn %O A143407 1,1 %A A143407 _T. D. Noe_, Aug 13 2008