|
|
A219341
|
|
Least prime k such that k*2^n + 1 divides 2^k - 1, or 0 if no such prime exists.
|
|
0
|
|
|
2, 3, 0, 11, 397, 839, 1459, 2081, 7297, 53849, 3499, 70589, 792277, 20399, 11173873, 929057, 232591, 6782759, 5834299, 26812151, 40269673, 88529891, 368454343, 616767917, 1167319801, 709939943, 38151887029, 38617336361, 23280518791, 168046587719, 882701485339
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
COMMENTS
|
If a(n) > 0, then a(n)*2^n + 1 is in A122094.
|
|
LINKS
|
|
|
MATHEMATICA
|
lst = {}; Do[k = 2; If[n == 2, AppendTo[lst, 0], While[True, If[PrimeQ[k], f = k*2^n + 1; If[PrimeQ[f] && PowerMod[2, k, f] == 1, AppendTo[lst, k]; Break[]]]; k++]], {n, 0, 13}]; lst
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|