|
|
A105181
|
|
Numbers k such that 2^(2*(k+1)) + 2^k - 1 is prime.
|
|
1
|
|
|
1, 2, 3, 4, 5, 6, 8, 10, 14, 22, 38, 42, 71, 118, 128, 159, 179, 214, 484, 951, 1148, 1162, 1427, 1532, 1692, 1861, 2261, 3760, 4575, 6974, 7295, 8367, 8463, 8600, 14878, 16165
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
|
|
EXAMPLE
|
2^4 + 2^1 + 1 = 19 is prime so a(1)=1.
2^6 + 2^2 + 1 = 67 is prime so a(2)=2.
2^8 + 2^3 + 1 = 263 is prime so a(3)=3.
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) [k: k in [0..200] | IsPrime(2^(2*(k+1))+2^k-1)]; // Jinyuan Wang, Mar 20 2020
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|