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 A057196 Numbers n such that 2^n + 9 is prime. 19
 1, 2, 3, 5, 6, 7, 9, 10, 18, 23, 30, 37, 47, 57, 66, 82, 95, 119, 175, 263, 295, 317, 319, 327, 670, 697, 886, 1342, 1717, 1855, 2394, 2710, 3229, 3253, 3749, 4375, 4494, 4557, 5278, 5567, 9327, 10129, 12727, 13615, 14893, 16473, 23639, 40053, 44399, 50335, 80949 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Some of the larger terms are only probable primes. For these numbers n, 2^(n-1)*(2^n+9) has deficiency 10, cf. A101223. - M. F. Hasler, Jul 18 2016 LINKS Robert Price, Table of n, a(n) for n = 1..56 Keith Conrad, Square patterns and infinitude of primes, University of Connecticut, 2019. H. Lifchitz & R. Lifchitz (Editors), PRP Top Records, of the form 2^n+9. MATHEMATICA Do[ If[ PrimeQ[ 2^n +9 ], Print[n]], { n, 1, 15000 }] PROG (PARI) for(n=1, 9e9, ispseudoprime(2^n+9)&&print1(n", ")) \\ M. F. Hasler, Jul 18 2016 CROSSREFS Cf. A104070 (primes of the form 2^n+3^2). [Klaus Brockhaus, Mar 14 2009] Cf. A059242, A057732, A019434, A057195, A057197. [M. F. Hasler, Jul 18 2016] Sequence in context: A179460 A171886 A018559 * A080637 A124134 A007071 Adjacent sequences:  A057193 A057194 A057195 * A057197 A057198 A057199 KEYWORD nonn AUTHOR Robert G. Wilson v, Sep 15 2000 EXTENSIONS More terms from Mike Oakes, Aug 17 2001 Edited by T. D. Noe, Oct 30 2008 STATUS approved

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Last modified October 20 20:24 EDT 2019. Contains 328273 sequences. (Running on oeis4.)