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 A241913 #15 Aug 27 2016 09:56:51
%S A241913 6,9,10,12,14,20,21,22,24,25,26,27,28,30,33,34,35,36,38,39,40,42,44,
%T A241913 46,48,49,51,52,54,56,57,58,60,62,63,65,66,68,69,70,72,74,75,76,77,78,
%U A241913 80,81,82,84,85,86,87,88,90,91,92,93,94,95,96,99,100,102,104,106,110,111
%N A241913 Complement of A241912, natural numbers not fixed by A241916.
%C A241913 Terms that occur in 2-cycles of permutation A241916. (E.g., A241916(6)=9, A241916(9)=6.)
%C A241913 Apart from its initial terms, 1 and 2, all the terms of A088902 occur here because A241909 has no other fixed points than 1 and 2.
%H A241913 Antti Karttunen, <a href="/A241913/b241913.txt">Table of n, a(n) for n = 1..10000</a>
%t A241913 f[n_] := If[n == 1, {0}, Function[f, ReplacePart[Table[0, {PrimePi[f[[-1, 1]]]}], #] &@ Map[PrimePi@ First@ # -> Last@ # &, f]]@ FactorInteger@ n]; g[w_List] := Times @@ Flatten@ MapIndexed[Prime[#2]^#1 &, w]; Complement[Range@ Max@ #, Table[#[[n + 1]]/2, {n, Length@ # - 1}]] &@ Select[Range@ 120, g@ f@ # == g@ Reverse@ f@ # &] (* _Michael De Vlieger_, Aug 27 2016 *)
%o A241913 (Scheme, with _Antti Karttunen_'s IntSeq-library)
%o A241913 (define A241913 (COMPLEMENT 1 A241912))
%Y A241913 Complement of A241912.
%Y A241913 A subsequence apart from its two initial terms: A088902.
%Y A241913 Cf. A241916.
%K A241913 nonn
%O A241913 1,1
%A A241913 _Antti Karttunen_, May 03 2014