|
|
A253774
|
|
Numbers k such that 4^k + 19 is prime.
|
|
2
|
|
|
1, 3, 15, 81, 327, 357, 685, 831, 861, 1405, 38571, 78127, 216487, 546121, 622615
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
15 is a term because 4^15 + 19 = 1073741843 is prime.
|
|
MATHEMATICA
|
Select[Range[3000], PrimeQ[4^# + 19] &]
|
|
PROG
|
(Magma) [n: n in [0..700] | IsPrime(4^n+19)];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|