|
| |
|
|
A124494
|
|
Numbers n for which 2n-1, 4n-1, 8n-1 and 16n-1 are primes.
|
|
6
|
|
|
|
3, 45, 90, 180, 255, 615, 705, 1350, 1770, 3225, 5295, 5775, 5955, 6060, 8580, 9855, 9945, 11175, 13095, 13740, 15195, 21825, 26820, 26925, 27615, 28920, 30075, 30705, 31710, 33375, 35700, 37350, 37665, 41250, 43770, 49185, 50700, 52185, 53640
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
Table of n, a(n) for n=1..39.
|
|
|
MATHEMATICA
|
Select[3*Range[20000], And @@ PrimeQ /@ ({2, 4, 8, 16}*# - 1) &] (*Chandler*)
|
|
|
CROSSREFS
|
Cf. A006254, A124485, A124493, A124017, A125113, A124514, A124515, A124516.
Sequence in context: A161589 A079038 A101790 * A075320 A071968 A093585
Adjacent sequences: A124491 A124492 A124493 * A124495 A124496 A124497
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Artur Jasinski, Nov 04 2006
|
|
|
EXTENSIONS
|
Extended by Ray Chandler, Nov 22 2006
|
|
|
STATUS
|
approved
|
| |
|
|