|
| |
|
|
A091704
|
|
Number of Barker codes of length n up to reversals and negations.
|
|
2
| |
|
|
2, 1, 2, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 2,1
|
|
|
COMMENTS
| It is conjectured that there are no Barker codes of length > 13.
|
|
|
REFERENCES
| R. H. Barker, Group synchronizing of binary digital sequences, in "Communication Theory", Butterworth, London, 1953, pp. 273-287.
H. D. Lueke, Korrelationssignale, Springer 1992.
|
|
|
LINKS
| Eric Weisstein's World of Mathematics, Barker Code
|
|
|
EXAMPLE
| {{+, +}, {+, -}}, {{+, +, -}}, {{+, +, +, -}, {+, +, -, +}}, {{+, +, +, -, +}}, {{+, +, +, -, -, +, -}}, {{+, +, +, -, -, -, +, -, -, +, -}}, {{+, +, +, +, +, -, -, +, +, -, +, -, +}}
|
|
|
CROSSREFS
| Cf. A011758, A011759.
Sequence in context: A105661 A082451 A121362 * A175799 A123739 A165575
Adjacent sequences: A091701 A091702 A091703 * A091705 A091706 A091707
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Eric Weisstein (eric(AT)weisstein.com), Jan 30, 2004
|
|
|
EXTENSIONS
| Comment changed by N. J. A. Sloane (njas(AT)research.att.com), Feb 03 2005
|
| |
|
|
