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 A057665 Numbers n such that prime(n)+2^prime(n) is prime. 3
 2, 3, 24, 66, 126 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(6) > 3002, since prime(3002) = 27479 (see comment by Ralf Stephan in A057663). - Michel Marcus, Dec 20 2013 These values correspond to indices ip = 2, 3, 9, 10, 11 where A052007(ip) is prime. - Michel Marcus, Dec 20 2013 LINKS FORMULA a(n) = primepi(A057663(n)). - Michel Marcus, Dec 20 2013 MATHEMATICA Select[Range[10^3], PrimeQ[# + 2^#] &@ Prime@ # &] (* Michael De Vlieger, Oct 26 2017 *) PROG (PARI) isok(n) = isprime(prime(n) + 2^prime(n)); \\ Michel Marcus, Dec 19 2013 CROSSREFS Cf. A052007, A057663, A057664. Sequence in context: A061355 A160618 A279335 * A157327 A009231 A012304 Adjacent sequences:  A057662 A057663 A057664 * A057666 A057667 A057668 KEYWORD nonn,more,hard AUTHOR Labos Elemer, Oct 16 2000 EXTENSIONS Name edited by Michel Marcus, Dec 19 2013 STATUS approved

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Last modified January 16 21:37 EST 2019. Contains 319206 sequences. (Running on oeis4.)