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A032421
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Numbers k such that 143*2^k+1 is prime.
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0
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53, 77, 293, 333, 393, 809, 825, 20973, 85349, 270285, 459093, 699189, 859769, 1650689
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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Table of n, a(n) for n=1..14.
Ray Ballinger, Proth Search Page
Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300
Y. Gallot, Proth.exe: Windows Program for Finding Large Primes
Wilfrid Keller, List of primes k.2^n - 1 for k < 300
Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime
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MATHEMATICA
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Select[Range[1000], PrimeQ[143*2^# + 1] & ] (* Robert Price, Dec 18 2018 *)
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PROG
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(PARI) is(n)=ispseudoprime(143*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
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CROSSREFS
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Sequence in context: A039389 A043212 A043992 * A129257 A125875 A059245
Adjacent sequences: A032418 A032419 A032420 * A032422 A032423 A032424
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KEYWORD
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nonn,hard,more
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AUTHOR
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James R. Buddenhagen
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EXTENSIONS
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a(10)-a(14) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018
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STATUS
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approved
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