OFFSET
0,1
COMMENTS
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".
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
LINKS
Chayim Lowen, Table of n, a(n) for n = 0..99
MATHEMATICA
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 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Chayim Lowen, Sep 12 2015
EXTENSIONS
Missing term 1092 inserted by Chayim Lowen, Mar 26 2017
STATUS
approved