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!)
A293862 Sequence of signed integers where each is chosen to be as small as possible (in absolute value) subject to the condition that no three terms a(j), a(j+k), a(j+2k) (for any j and k) form an arithmetic progression; in case of a tie, preference is given to the positive value. 2
0, 0, 1, 0, 0, 1, 1, -1, -1, 0, 0, -1, 0, 0, 1, 3, 3, -1, 3, 3, 1, 1, 2, 2, 1, -3, 2, 0, 0, -2, 0, 0, 1, -3, -3, -2, 0, 0, 4, 0, 0, 1, -2, -1, -1, -2, 5, -1, 3, -3, 2, 3, 3, 2, 5, 4, 4, 2, 4, 2, 3, -1, -1, 3, -8, -2, 5, 2, -2, -2, -8, -3, -2, -8, -6, -6, 2, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,16
COMMENTS
This sequence is a "signed" variant of A229037. Graphically, both sequences have similar ethereal features.
For any n > 0, |a(n)| <= floor( (n+1)/4 ).
LINKS
EXAMPLE
a(1) = 0 is suitable.
a(2) = 0 is suitable.
a(3) cannot equal 0 as 2*a(3-1) - a(3-2) = 0.
a(3) = 1 is suitable.
a(4) cannot equal 2 as 2*a(4-1) - a(4-2) = 2.
a(4) = 0 is suitable.
a(5) cannot equal -1 as 2*a(5-1) - a(5-2) = -1.
a(5) cannot equal 2 as 2*a(5-2) - a(5-4) = 2.
a(5) = 0 is suitable.
a(6) cannot equal 0 as 2*a(6-1) - a(6-2) = 0.
a(6) = 1 is suitable.
a(7) cannot equal 2 as 2*a(7-1) - a(7-2) = 2.
a(7) cannot equal -1 as 2*a(7-2) - a(7-4) = -1.
a(7) cannot equal 0 as 2*a(7-3) - a(7-6) = 0.
a(7) = 1 is suitable.
a(8) cannot equal 1 as 2*a(8-1) - a(8-2) = 1.
a(8) cannot equal 2 as 2*a(8-2) - a(8-4) = 2.
a(8) cannot equal 0 as 2*a(8-3) - a(8-6) = 0.
a(8) = -1 is suitable.
PROG
(C++) See Links section.
CROSSREFS
Sequence in context: A039992 A101988 A200606 * A295676 A088420 A103585
KEYWORD
sign
AUTHOR
Rémy Sigrist, Oct 18 2017
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 March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)