|
|
A045536
|
|
Primes p such that p+2 and 2p+1 are also prime.
|
|
18
|
|
|
3, 5, 11, 29, 41, 179, 191, 239, 281, 419, 431, 641, 659, 809, 1019, 1031, 1049, 1229, 1289, 1451, 1481, 1931, 2129, 2141, 2339, 2549, 2969, 3299, 3329, 3359, 3389, 3539, 3821, 3851, 4019, 4271, 4481, 5231, 5279, 5441, 5501, 5639, 5741, 5849, 6131
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
MAPLE
|
select(t -> isprime(t) and isprime(t+2) and isprime(2*t+1), [3, seq(t, t=5..10000, 6)]); # Robert Israel, Feb 28 2017
|
|
MATHEMATICA
|
|
|
PROG
|
(Magma) [p: p in PrimesUpTo(6200) | IsPrime(p+2) and IsPrime(2*p+1)]; // Vincenzo Librandi, Apr 08 2013
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
Name changed and incorrect comment and program removed by T. D. Noe, Aug 05 2010
|
|
STATUS
|
approved
|
|
|
|