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A002257
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Numbers n such that 13*4^n + 1 is prime.
(Formerly M3247 N1310)
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1
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1, 4, 5, 10, 14, 41, 94, 154, 158, 500, 14140, 19004, 21928, 44009, 54629, 57148, 260653, 281228, 342280, 519448, 749938, 930866
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OFFSET
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1,2
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REFERENCES
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H. Riesel, "Prime numbers and computer methods for factorization," Progress in Mathematics, Vol. 57, Birkhauser, Boston, 1985, Chap. 4, see pp. 381-384.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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MATHEMATICA
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Select[Range[2000], PrimeQ[13 4^#+1]&] (* Harvey P. Dale, Jan 22 2011 *)
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PROG
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(PARI) for(n=1, 10^5, if(ispseudoprime(13*4^n+1), print1(n, ", "))); /* Joerg Arndt, Apr 07 2013 */
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CROSSREFS
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See A032356 (n such that 13*2^n+1 is prime) for more terms.
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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