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 A077093 #15 May 06 2025 16:54:17
%S A077093 1,4,24,7530,12100,32784,34950,69480,121104,420096,1018980,2846484,
%T A077093 2946560,4160040,5387484,5512800,5729520,13108800,23524452,24799080,
%U A077093 25885760,31382952,53344272,100929036,150057300,352636452
%N A077093 Smallest initial values leading to fixed points listed in A077092.
%e A077093 n=12100: FixedPointList={12100,24000,34944},end=34944; n=121104: FixedPointList={121104,268560}, end=268560.
%t A077093 f[x_] := EulerPhi[DivisorSigma[1, x]-EulerPhi[x]]; Do[s=NestList[f, n, 100]; s1=Part[s, 99]; s2=Part[s, 100]; If[Equal[s1, s2]&&!PrimeQ[n], Print[{n, s1}]], {n, 1, 1000}] (*n=site if fixed point appears; s1=fixed point*)
%Y A077093 Cf. A077090, A077091, A077092, A077094, A077095, A077096, A077099, A077100.
%K A077093 nonn,more
%O A077093 1,2
%A A077093 _Labos Elemer_, Oct 31 2002
%E A077093 a(11)-a(26) from _Sean A. Irvine_, May 06 2025