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A137702
Prime numbers p such that p +- ((p-1)/2) are primes.
2
5, 13, 73, 421, 541, 613, 661, 673, 1201, 1453, 2341, 2473, 2593, 3061, 3313, 4441, 4561, 5113, 6073, 6121, 6133, 8521, 8893, 9601, 9901, 10453, 11161, 11701, 12301, 12721, 13381, 13681, 13933, 15241, 15361, 15373, 15733, 16033, 16333, 16381
OFFSET
1,1
LINKS
EXAMPLE
(5-2, 5+2) are prime
(13-6, 13+6) are prime
MATHEMATICA
Select[Prime[Range[1000]], PrimeQ[#-(#-1)/2] && PrimeQ[#+(#-1)/2]&]
PROG
(PARI) forprime(p=3, 1e5, if(isprime(p+p\2)&isprime(p\2+1), print1(p", ")))
CROSSREFS
Cf. A174734.
Sequence in context: A139361 A115329 A272645 * A140120 A303962 A304927
KEYWORD
nonn,easy
AUTHOR
STATUS
approved