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A107438 Primes p such that 7*p+2 or 2*p+7 is prime. 1
2, 3, 5, 11, 17, 23, 41, 47, 53, 71, 83, 101, 107, 113, 131, 137, 167, 173, 191, 197, 227, 251, 257, 281, 293, 311, 317, 347, 353, 383, 401, 431, 461, 467, 503, 521, 563, 587, 593, 641, 647, 677, 683, 701, 743, 773, 797, 821, 827, 857, 863, 887, 911, 941, 947 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
Select[Prime[Range[220]], PrimeQ[2#+7]||PrimeQ[7#+2]&] (* Shepherd *)
PROG
(PARI) isok(n) = isprime(n) && (isprime(7*n+2) || isprime(2*n+7)); \\ Michel Marcus, Oct 06 2013
CROSSREFS
Cf. A105760 Numbers n such that (2*n + 7) is prime; A105772 Numbers n such that (7*n + 2) is prime.
Sequence in context: A049553 A049595 A258039 * A211204 A023206 A359555
KEYWORD
nonn
AUTHOR
Zak Seidov, May 26 2005
EXTENSIONS
Edited by Rick L. Shepherd, Feb 01 2006
STATUS
approved

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Last modified July 16 17:03 EDT 2024. Contains 374358 sequences. (Running on oeis4.)