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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A085423 a(n) = floor(log_2(3n)). 4
1, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Length of the symmetric signed digit expansion of n with q=2 (i.e. the length of the representation of n in the (-1,0,1)_2 number system).

LINKS

Table of n, a(n) for n=1..96.

C. Heuberger and H. Prodinger, On minimal expansions in redundant number systems: Algorithms and quantitative analysis, Computing 66(2001), 377-393.

FORMULA

a(n) = A000523(A008585(n)). - Reinhard Zumkeller, Mar 16 2013

MATHEMATICA

Floor[Log[2, 3*Range[100]]] (* Harvey P. Dale, Oct 15 2016 *)

PROG

(Haskell)

a085423 = a000523 . a008585  -- Reinhard Zumkeller, Mar 16 2013

CROSSREFS

Cf. A005578.

Sequence in context: A194847 A262070 A117806 * A260998 A324728 A327008

Adjacent sequences:  A085420 A085421 A085422 * A085424 A085425 A085426

KEYWORD

nonn,easy

AUTHOR

Ralf Stephan, Jun 30 2003

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 January 27 12:01 EST 2020. Contains 331295 sequences. (Running on oeis4.)