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 A122721 Numbers n such that abs(7^n - 2^11) is prime. 0
 2, 4, 5, 6, 9, 21, 41, 52, 58, 118, 130, 585, 614, 744, 881, 941, 966, 1280, 1658, 4985 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..20. C. Pomerance, Science News reference. EXAMPLE For x = 2 abs(7^2-2^11) = 1999 which is prime. So 2 is the first entry. PROG (PARI) g(n) = for(x=1, n, y=abs(7^x-2^11); if(ispseudoprime(y), print1(x", "))) CROSSREFS Sequence in context: A003306 A250305 A136585 * A014224 A175342 A077312 Adjacent sequences: A122718 A122719 A122720 * A122722 A122723 A122724 KEYWORD easy,nonn AUTHOR Cino Hilliard, Sep 23 2006 STATUS approved

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Last modified June 2 07:25 EDT 2023. Contains 363081 sequences. (Running on oeis4.)