|
|
A240663
|
|
Least k such that 8^k == -1 (mod prime(n)), or 0 if no such k exists.
|
|
1
|
|
|
0, 1, 2, 0, 5, 2, 4, 3, 0, 14, 0, 6, 10, 7, 0, 26, 29, 10, 11, 0, 0, 0, 41, 0, 8, 50, 0, 53, 6, 14, 0, 65, 34, 23, 74, 0, 26, 27, 0, 86, 89, 30, 0, 16, 98, 0, 35, 0, 113, 38, 0, 0, 4, 25, 8, 0, 134, 0, 46, 35, 47, 146, 17, 0, 26, 158, 5, 0, 173, 58, 44, 0, 0, 62
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
The least k, if it exists, such that prime(n) divides 8^k + 1.
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Table[p = Prime[n]; s = Select[Range[p/2], PowerMod[8, #, p] == p - 1 &, 1]; If[s == {}, 0, s[[1]]], {n, 100}]
|
|
CROSSREFS
|
Cf. A211244 (order of 8 mod prime(n)).
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|