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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A118824 2-adic continued fraction of zero, where a(n) = if n=1(mod 2), -2, else +1*A006519(n/2). 5
-2, 1, -2, 2, -2, 1, -2, 4, -2, 1, -2, 2, -2, 1, -2, 8, -2, 1, -2, 2, -2, 1, -2, 4, -2, 1, -2, 2, -2, 1, -2, 16, -2, 1, -2, 2, -2, 1, -2, 4, -2, 1, -2, 2, -2, 1, -2, 8, -2, 1, -2, 2, -2, 1, -2, 4, -2, 1, -2, 2, -2, 1, -2, 32, -2, 1, -2, 2, -2, 1, -2, 4, -2, 1, -2, 2, -2, 1, -2, 8, -2, 1, -2, 2, -2, 1, -2, 4, -2, 1, -2, 2, -2, 1, -2, 16, -2, 1, -2, 2, -2, 1 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Limit of convergents equals zero; only the 6-th convergent is indeterminate. Other 2-adic continued fractions of zero are: A118821, A118827, A118830. A006519(n) is the highest power of 2 dividing n; A080277 = partial sums of A038712, where A038712(n) = 2*A006519(n) - 1.

EXAMPLE

For n>=1, convergents A118825(k)/A118826(k) are:

at k = 4*n: 1/A080277(n);

at k = 4*n+1: 2/(2*A080277(n)-1);

at k = 4*n+2: 1/(A080277(n)-1);

at k = 4*n-1: 0.

Convergents begin:

-2/1, -1/1, 0/-1, -1/-1, 2/1, 1/0, 0/1, 1/4,

-2/-7, -1/-3, 0/-1, -1/-5, 2/9, 1/4, 0/1, 1/12,

-2/-23, -1/-11, 0/-1, -1/-13, 2/25, 1/12, 0/1, 1/16,

-2/-31, -1/-15, 0/-1, -1/-17, 2/33, 1/16, 0/1, 1/32, ...

PROG

(PARI) a(n)=local(p=-2, q=+1); if(n%2==1, p, q*2^valuation(n/2, 2))

CROSSREFS

Cf. A006519, A080277; convergents: A118825/A118826; variants: A118821, A118827, A118830; A100338.

Sequence in context: A099910 A043555 A118821 * A082641 A138553 A069016

Adjacent sequences:  A118821 A118822 A118823 * A118825 A118826 A118827

KEYWORD

cofr,sign

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), May 01 2006

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 16 10:53 EST 2012. Contains 205904 sequences.