A262149 Rocket sequence 50: a(0)=50, a(n)=A073846(a(n-1)).

50, 97, 68, 139, 94, 211, 140, 349, 222, 607, 378, 1129, 689, 427, 272, 769, 476, 1493, 901, 552, 1783, 1072, 3863, 2268, 9151, 5275, 3077, 1819, 1092, 3931, 2308, 9323, 5370, 24113, 13671, 7825, 4528, 20021, 11385, 6537, 3796, 16363, 9336, 44927, 25250

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

Formula

a(n+1) = A073846(a(n)).

a(n-1) = A073898(a(n)).

Example

a(1) = A073846(a(0)) = A073846(50) = 97.

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

Cf. A073846, A261314, A261621.

Sequence in context: A138381 A349208 A224551 * A228953 A335480 A255585

Adjacent sequences: A262146 A262147 A262148 * A262150 A262151 A262152

Keyword

nonn

Author

Chayim Lowen, Sep 12 2015

Extensions

Missing term 1092 inserted by Chayim Lowen, Mar 26 2017

Status

approved