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 A348214 #7 Oct 08 2021 22:36:46
%S A348214 1,2,64,50624,235053,15800785,36903321,4038974856
%N A348214 a(n) is the least number k such that A348213(k) = n, or -1 if no such number exists.
%e A348214 n The n iterations of a(n) under the map x -> A348158(x)
%e A348214 - --------------------------------------------------------------------------------
%e A348214 0 1
%e A348214 1 2 -> 1
%e A348214 2 64 -> 63 -> 57
%e A348214 3 50624 -> 49833 -> 49155 -> 48819
%e A348214 4 235053 -> 231363 -> 223245 -> 222885 -> 210693
%e A348214 5 15800785 -> 15775305 -> 15763125 -> 15761925 -> 15208875 -> 14889335
%e A348214 6 36903321 -> 36323991 -> 35049465 -> 34992945 -> 33078801 -> 32940117 -> 29802963
%e A348214 7 4038974856 -> 2855346375 -> 2854284615 -> 2556863361 -> 2549117805 -> 2536180173 -> 2447191395 -> 2445883515
%t A348214 f[n_] := Plus @@ DeleteDuplicates @ Map[EulerPhi, Divisors[n]]; s[n_] := -2 + Length @ FixedPointList[f, n]; seq[m_, lim_] := Module[{t = Table[0, {m}], c = 0, n = 1}, While[c < m && n < lim, i = s[n] + 1; If[i <= m && t[[i]] == 0, c++; t[[i]] = n]; n++]; TakeWhile[t, # > 0 &]]; seq[5, 10^6]
%Y A348214 Cf. A007755, A348158, A348213.
%K A348214 nonn,more
%O A348214 0,2
%A A348214 _Amiram Eldar_, Oct 07 2021