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 A073320 #9 Nov 16 2017 15:52:22
%S A073320 4,5,8,9,13,16,17,18,22,23,24,27,31,35,36,40,41,46,47,56,64,69,70,71,
%T A073320 89,90,91,92,93,94,95,103,109,110,111,112,113,146,147,161,162,163,171,
%U A073320 172,173,174,196,240,241,242,243,261,262,263,277,438,439,440,1137,1138
%N A073320 A073259(n)=3: the length of iteration transient leading to n-th composite number equals 3.
%F A073320 See Program.
%e A073320 The sequence is most probably complete. a(1)=4: the fixed point list from m=a(1) to composite[m] is: {4,7,9}, the length is 3; last term is a(64)=1142 with transient list {1142,1332,1360}.
%t A073320 lfp[x_] := Length[FixedPointList[x+PrimePi[ # ]+1&, x]]-1 Do[s=lfp[n]; If[Equal[s, 3], Print[n]], {n, 1, 10000000}]
%Y A073320 Cf. A002808, A073259.
%K A073320 fini,full,nonn
%O A073320 1,1
%A A073320 _Labos Elemer_, Jul 29 2002