|
|
A211487
|
|
Characteristic sequence of numbers n having a primitive root modulo n.
|
|
6
|
|
|
0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1
|
|
COMMENTS
|
a(1) = 0, since we have an empty set of numbers more than 0 and less than 1.
If A(x) is the counting function of a(n)=1, n<=x, then A(x)~2*x/log(x) as x tends to infinity.
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 1 iff n = 2, 4, p^k, 2*p^k, where p is an odd prime.
For n > 1, if A034380(n) = 1, a(n) = 1, otherwise a(n) = 0.
(End)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|