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 A153776 #8 Aug 28 2016 03:11:38
%S A153776 1,2,4,7,9,17,19,32,34,42,44,82,84,92,94,157,159,167,169,207,209,217,
%T A153776 219,407,409,417,419,457,459,467,469,782,784,792,794,832,834,842,844,
%U A153776 1032,1034,1042,1044,1082,1084,1092,1094,2032,2034,2042,2044,2082,2084
%N A153776 Sequence S such that 1 is in S and if x is in S, then 5x-3 and 5x-1 are in S.
%C A153776 Subsequences include A047850, A083065.
%C A153776 First generation: 1
%C A153776 2nd generation: 2, 4
%C A153776 3rd generation: 7, 9, 17, 19
%C A153776 4th generation: 32, 34, 42, 44, 82, 84, 92, 94
%C A153776 Does every generation contain p or 2p for some prime p?
%H A153776 G. C. Greubel, <a href="/A153776/b153776.txt">Table of n, a(n) for n = 1..1000</a>
%t A153776 nxt[n_] := Flatten[5 # + {-3, -1} & /@ n]; Union[Flatten[NestList[nxt, {1}, 5]]] (* _G. C. Greubel_, Aug 28 2016 *)
%Y A153776 Cf. A047850, A083065, A153773, A153775.
%K A153776 nonn
%O A153776 1,2
%A A153776 _Clark Kimberling_, Jan 02 2009