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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108960 n expressed in Fibonacci binary-like number system using only 1's and 2's. 0
1, 2, 12, 22, 121, 221, 122, 1211, 2211, 1221, 1212, 2212, 1222, 2222, 12211, 12121, 22121, 12221, 22221, 12212, 12122, 22122, 12222, 121211, 221211, 122211, 222211, 122121, 121221, 221221, 122221, 121212, 221212, 122212, 222212, 122122, 121222 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

We have, for instance, a(16)=12121 because 16 = 1*(5) + 2*(3) + 1*(2) + 2*(1) + 1*(1) = 1*F(5) + 2*F(4) + 1*F(3) + 2*F(2) + 1*F(1).

Comments from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 12 2008 (Start) (i) The representation chosen here is that the leftmost digit of a(n) refers to the coefficient of F(1)=1, the second from the left to the coefficient of F(2)=1 etc.

(ii) If one would minimize the length of the representation, one would select a(8)=222 = 2*F(1)+2*F(2)+2*F(3)=2*1+2*1+2*2, with 3 digits, not a(8)=1211 =1*F(1)+2*F(2)+1*F(3)+1*F(4) with four digits.

(iii) If one would minimize the decimal value of a(n), one would get the sequence 1, 2, 12, 22, 121, 112, 122, 222, 1121, 1112 etc.

We are essentially dealing with the output of a web program which does not document which of the non-unique representations is actually chosen. (End)

LINKS

K. Levasseur, A Fibonacci Number System

CROSSREFS

Sequence in context: A189330 A120672 A190642 * A111095 A073211 A094626

Adjacent sequences:  A108957 A108958 A108959 * A108961 A108962 A108963

KEYWORD

nonn

AUTHOR

Lekraj Beedassy (blekraj(AT)yahoo.com), Jul 22 2005

EXTENSIONS

More terms from David Wasserman (dwasserm(AT)earthlink.net), May 22 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 21:27 EST 2012. Contains 205859 sequences.