login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A153775 Sequence S such that 1 is in S and if x is in S, then 3x-1 and 3x are in S. 6
1, 2, 3, 5, 6, 8, 9, 14, 15, 17, 18, 23, 24, 26, 27, 41, 42, 44, 45, 50, 51, 53, 54, 68, 69, 71, 72, 77, 78, 80, 81, 122, 123, 125, 126, 131, 132, 134, 135, 149, 150, 152, 153, 158, 159, 161, 162, 203, 204, 206, 207, 212, 213, 215, 216, 230, 231, 233, 234, 239, 240, 242 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Subsequences include A007051, A000244, A153773, A153774.

First generation: 1

2nd generation: 2, 3

3rd generation: 5, 6, 8, 9

4th generation: 14, 15, 17, 18, 23, 24, 26, 27

Does every generation contain a prime?

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

MATHEMATICA

nxt[n_] := Flatten[3 # + {-1, 0} & /@ n]; Union[Flatten[NestList[nxt, {1}, 5]]] (* G. C. Greubel, Aug 28 2016 *)

CROSSREFS

Cf. A007051, A000244, A147992, A153773, A153774.

Sequence in context: A226806 A058588 A035399 * A173666 A063756 A117522

Adjacent sequences:  A153772 A153773 A153774 * A153776 A153777 A153778

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 02 2009

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 16 04:26 EDT 2019. Contains 325064 sequences. (Running on oeis4.)