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 A262149 #43 Apr 03 2017 11:14:13
%S A262149 50,97,68,139,94,211,140,349,222,607,378,1129,689,427,272,769,476,
%T A262149 1493,901,552,1783,1072,3863,2268,9151,5275,3077,1819,1092,3931,2308,
%U A262149 9323,5370,24113,13671,7825,4528,20021,11385,6537,3796,16363,9336,44927,25250
%N A262149 Rocket sequence 50: a(0)=50, a(n)=A073846(a(n-1)).
%C A262149 This sequence has been checked up to a(98) = 1078406742163 without reaching 50. It seems to be slowly climbing in value in both the negative and positive directions. Hence, its period is either extremely large or, as I conjecture, infinite. Thus I dubbed the sequence "Rocket" because, as opposed the "Hailstone" sequences, it never seems to "fall".
%C A262149 This sequence, when extended to all integers using a(n-1) = A073898(a(n)), is R#(50), see A073846 for definition. - _Chayim Lowen_, Jan 25 2016
%H A262149 Chayim Lowen, <a href="/A262149/b262149.txt">Table of n, a(n) for n = 0..99</a>
%F A262149 a(n+1) = A073846(a(n)).
%F A262149 a(n-1) = A073898(a(n)).
%e A262149 a(1) = A073846(a(0)) = A073846(50) = 97.
%t A262149 s = Module[{p = Prime@ Range@ PrimePi@ #, c}, c = Complement[Range@ #, p]; Riffle[Take[c, Length@ p], p]] &[5*10^5]; NestList[s[[#]] &, 50, 44] (* _Michael De Vlieger_, Jan 27 2016, after _Harvey P. Dale_ at A073846 *)
%Y A262149 Cf. A073846, A261314, A261621.
%K A262149 nonn
%O A262149 0,1
%A A262149 _Chayim Lowen_, Sep 12 2015
%E A262149 Missing term 1092 inserted by _Chayim Lowen_, Mar 26 2017