OFFSET
1,2
COMMENTS
Odd terms of A308149.
After a(2), each term's Collatz trajectory includes 256.
A plot of a(n)/n vs. n has an interesting quasiperiodic form with a decreasing frequency. Does lim_{n->infinity} a(n)/n equal 32?
LINKS
EXAMPLE
The Collatz trajectories of the first few terms are as follows:
.
n a(n) trajectory
-- ---- ------------------------------------------------------------
1 1 1
2 21 21, 64, 32, 16, 8, 4, 2, 1
3 75 75, 226, 113, 340, 170, 85, 256, 128, 64, 32, 16, 8, 4, 2, 1
4 85 85, 256, 128, 64, 32, 16, 8, 4, 2, 1
5 113 113, 340, 170, 85, 256, 128, 64, 32, 16, 8, 4, 2, 1
MATHEMATICA
Select[Range[1, 1500, 2], !MemberQ[NestWhileList[If[OddQ[#1], 3*#1 + 1, #1/2] &, #, #1 > 1 &], 5] &] (* Amiram Eldar, Dec 18 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jon E. Schoenfield, Dec 17 2021
STATUS
approved