|
| |
|
|
A048669
|
|
Jacobsthal function: maximal distance between integers relatively prime to n.
|
|
10
| |
|
|
1, 2, 2, 2, 2, 4, 2, 2, 2, 4, 2, 4, 2, 4, 3, 2, 2, 4, 2, 4, 3, 4, 2, 4, 2, 4, 2, 4, 2, 6, 2, 2, 3, 4, 3, 4, 2, 4, 3, 4, 2, 6, 2, 4, 3, 4, 2, 4, 2, 4, 3, 4, 2, 4, 3, 4, 3, 4, 2, 6, 2, 4, 3, 2, 3, 6, 2, 4, 3, 6, 2, 4, 2, 4, 3, 4, 3, 6, 2, 4, 2, 4, 2, 6, 3, 4, 3, 4, 2, 6, 3, 4, 3, 4, 3, 4, 2, 4, 3, 4, 2, 6, 2, 4, 5
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Differs from A070194 by 1 at the primes. - T. D. Noe, Mar 21 2007
|
|
|
REFERENCES
| E. Jacobsthal, Uber Sequenzen ganzer Zahlen, von denen keine zu n teilerfremd ist, I, II, III. Norske Videnskabsselskab Forhdl., 33, 1960, 117-139
P. Erdos, On the integers relatively prime to n and on a number theoretic function considered by Jacobsthal. Math. Scand., 10, 1962, 163-170
H. Iwaniec, On the problem of Jacobsthal. Demo. Math., 11, 1978, 225-231
|
|
|
LINKS
| T. D. Noe, Table of n, a(n) for n=1..10000
|
|
|
EXAMPLE
| a(6)=4 because the gap between 1 and 5, both being relatively prime to 6, is maximal and 5-1 = 4.
|
|
|
CROSSREFS
| Cf. A048670. Essentially same as A049298. See A132468 for another version.
Cf. A070971.
Sequence in context: A122066 A053238 A058263 * A158522 A034444 A073180
Adjacent sequences: A048666 A048667 A048668 * A048670 A048671 A048672
|
|
|
KEYWORD
| nonn,easy,nice
|
|
|
AUTHOR
| Jan Kristian Haugland (jankrihau(AT)hotmail.com)
|
| |
|
|
