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A027615 Number of 1's when n is written in base -2. 0
0, 1, 2, 3, 1, 2, 3, 4, 2, 3, 4, 5, 3, 4, 2, 3, 1, 2, 3, 4, 2, 3, 4, 5, 3, 4, 5, 6, 4, 5, 3, 4, 2, 3, 4, 5, 3, 4, 5, 6, 4, 5, 6, 7, 5, 6, 4, 5, 3, 4, 5, 6, 4, 5, 3, 4, 2, 3, 4, 5, 3, 4, 2, 3, 1, 2, 3, 4, 2, 3, 4, 5, 3, 4, 5, 6, 4, 5, 3, 4, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Base -2 is also called "negabinary".

REFERENCES

J.-P. Allouche and J. Shallit, Automatic Sequences, Cambridge Univ. Press, 2003, p. 164.

LINKS

Table of n, a(n) for n=0..80.

Eric Weisstein's World of Mathematics, Negabinary.

FORMULA

a(n) = 3 * A072894(n+1) - 2n - 3. Proof by Nikolaus Meyberg, following a conjecture by Ralf Stephan. - R. J. Mathar, Jan 11 2013

CROSSREFS

Cf. A072894.

Sequence in context: A104246 A007720 A129968 * A053737 A033924 A276328

Adjacent sequences:  A027612 A027613 A027614 * A027616 A027617 A027618

KEYWORD

nonn

AUTHOR

Pontus von Brömssen, Nov 14 1997

STATUS

approved

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Last modified December 8 06:50 EST 2016. Contains 278902 sequences.