|
| |
|
|
A117549
|
|
Values of n for which there exist d(1),...,d(n), each in {0,1,...,4} and an r in {1,...,4} such that Sum[d(i)d(i+k),i=1,n-k]=r (mod 5) for all k=0,...,n-1. (Such a sequence is called a very(5,r) sequence. See the link.).
|
|
1
| | |
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Conjecture. Let A be a very(5,1) (respectively very(5,4)) sequence of length n and let Z be a sequence of n-1 0's.. Then AZ(3A)ZA is a very(5,1) (respectively very(5,4)) sequence of length 5n-2. (Here 3A denotes the result of multiplying each term of A by 3, then reducing modulo 5; and juxtaposition of symbols denotes concatenation of sequences.)
|
|
|
LINKS
| John W. Layman, On A Generalization of Very Odd Sequences
|
|
|
CROSSREFS
| Cf. A053006, A117548, A117550, A117551.
Sequence in context: A028357 A168241 A099822 * A190767 A028433 A080667
Adjacent sequences: A117546 A117547 A117548 * A117550 A117551 A117552
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| John W. Layman (layman(AT)math.vt.edu), Apr 21 2006
|
| |
|
|
