|
|
A217381
|
|
Numbers n such that 8^n + 7 is prime.
|
|
1
|
|
|
2, 6, 10, 26, 42, 58, 68, 196, 266, 602, 1170, 1288, 1290, 2990, 4110, 6292, 7446, 36928, 57490, 65478, 78570, 188832
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
All terms are equal to 1/3 of the multiples of 3 in A057195.
Naturally these numbers are even because (9-1)^(2n+1)+7 is divisible by 3. - Bruno Berselli, Oct 03 2012
|
|
LINKS
|
|
|
MATHEMATICA
|
Select[Range[10000], PrimeQ[8^# + 7] &]
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|