The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A308149 Positive integers with Collatz trajectories that do not include the number 5. 0
 1, 2, 4, 8, 16, 21, 32, 42, 64, 75, 84, 85, 113, 128, 150, 151, 168, 170, 201, 226, 227, 256, 267, 300, 301, 302, 336, 340, 341, 401, 402, 403, 423, 452, 453, 454, 475, 512, 534, 535, 537, 600, 602, 604, 605, 633, 635, 672, 680, 682, 713, 715, 802, 803, 804, 805, 806, 846, 847, 891, 904, 906, 908, 909, 950, 951, 953, 955 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A consequence of the Collatz conjecture is that, after a(5), this would be equivalent to the list of positive integers with Collatz trajectories that include the number 32. LINKS Anonymous, Archive of /sci/ - Conjecture. EXAMPLE 21 is a term because its Collatz trajectory, given in A033481, does not include 5. MATHEMATICA collatzTrajectory[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Select[Range[1000], Not[MemberQ[collatzTrajectory[#], 5]] &] (* Alonso del Arte, May 25 2019 *) CROSSREFS Cf. A006370, A033481, A070165. A000079 is a subsequence. Sequence in context: A045776 A102252 A174838 * A196871 A334423 A001856 Adjacent sequences:  A308146 A308147 A308148 * A308150 A308151 A308152 KEYWORD nonn,easy AUTHOR Nathan Bumber, May 14 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 24 12:31 EDT 2021. Contains 347642 sequences. (Running on oeis4.)