The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137305 Write n in base 3, change twos in ones and ones in twos, reverse. 1
0, 2, 1, 2, 8, 5, 1, 7, 4, 2, 20, 11, 8, 26, 17, 5, 23, 14, 1, 19, 10, 7, 25, 16, 4, 22, 13, 2, 56, 29, 20, 74, 47, 11, 65, 38, 8, 62, 35, 26, 80, 53, 17, 71, 44, 5, 59, 32, 23, 77, 50, 14, 68, 41, 1, 55, 28, 19, 73, 46, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
This is not to A036044 as A007089 is to A007088: despite similarity here the operation performed is not a base 3 complement. Fixed points begin: 5, 7, 11, 19, 29, 44, 50, 55.
LINKS
FORMULA
a(3^n) = 2. a(2*3^n) = 1.
EXAMPLE
53 -> 1222 -> 2111 -> 1112 -> 41.
MAPLE
a:= proc(n) local m, r; m, r:= n, 0; while m>0
do r:=r*3+[0, 2, 1][1+irem(m, 3, 'm')] od; r
end:
seq(a(n), n=0..100); # Alois P. Heinz, Jun 20 2016
MATHEMATICA
a[n_] := FromDigits[ Reverse[ IntegerDigits[n, 3] /. {1 -> 2, 2 -> 1}], 3] (* Giovanni Resta, Jun 20 2016 *)
CROSSREFS
Sequence in context: A334729 A221878 A219109 * A282885 A242841 A143208
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Apr 20 2008
EXTENSIONS
Edited and corrected by Giovanni Resta, Jun 20 2016
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 21 13:22 EDT 2024. Contains 372736 sequences. (Running on oeis4.)