|
Search: id:A046693
|
|
|
| A046693 |
|
Size of smallest subset S of N={0,1,2,...,n} such that S-S=N, where S-S={abs(i-j) | i,j in S}. |
|
+0
1
|
|
| 1, 2, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
It is easy to show that a(n+1) must be no larger than a(n)+1. Problem: Can a(n+1) ever be smaller than a(n)?
|
|
REFERENCES
|
Related to 'The set of differences of a given set', by Andrew Granville and Friedrich Roesler, Amer. Math. Monthly, 106 (1999), 338-344.
|
|
LINKS
|
A. Granville and F. Roesler, The set of differences of a given set
|
|
EXAMPLE
|
a(10)=6, since all integers in {0,1,2...10} are differences of elements of {0,1,2,3,6,10}, but not of any 5-element set.
|
|
CROSSREFS
|
Sequence in context: A083398 A061420 A003057 this_sequence A156077 A058889 A166724
Adjacent sequences: A046690 A046691 A046692 this_sequence A046694 A046695 A046696
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Johm W. Layman (layman(AT)math.vt.edu)
|
|
|
Search completed in 0.004 seconds
|
