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A182785
Primes p such that 2*p^4-1 is also prime.
6
2, 5, 7, 47, 79, 103, 131, 139, 149, 173, 197, 229, 307, 313, 331, 373, 439, 541, 547, 593, 659, 743, 761, 797, 853, 859, 863, 883, 919, 937, 1051, 1093, 1097, 1163, 1171, 1301, 1303, 1451, 1471, 1549, 1601, 1657, 1721, 1861, 1973, 2039, 2081, 2087, 2099, 2129, 2161, 2239, 2269, 2393, 2417, 2437, 2473, 2521
OFFSET
1,1
LINKS
FORMULA
A000040 INTERSECT A182783.
MATHEMATICA
Select[Prime[Range[500]], PrimeQ[2 #^4 - 1]&] (* Vincenzo Librandi, Apr 17 2013 *)
PROG
(Magma) [p: p in PrimesUpTo(2600)| IsPrime(2*p^4 - 1)]; // Vincenzo Librandi, Apr 17 2013
CROSSREFS
Cf. A182783, A182784, A106483 (2p^2-1 prime), A177104 (2p^3-1 prime), A309855 (2p^5-1 prime).
Sequence in context: A215213 A069356 A041653 * A358381 A041125 A293592
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 02 2010
STATUS
approved