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 A032461 Numbers k such that 169*2^k+1 is prime. 0
 2, 14, 26, 158, 282, 298, 406, 522, 534, 1050, 1470, 1478, 1614, 1970, 2570, 5054, 5166, 6238, 9614, 14026, 49602, 63686, 70110, 76934, 109666, 167734, 223590, 602070, 801578, 1327114, 1635086, 2545526 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..32. Ray Ballinger, Proth Search Page Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300 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 MATHEMATICA Select[Range[1000], PrimeQ[169*2^# + 1] & ] (* Robert Price, Dec 18 2018 *) PROG (PARI) is(n)=ispseudoprime(169*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Sequence in context: A109080 A295083 A180877 * A072390 A213136 A117705 Adjacent sequences: A032458 A032459 A032460 * A032462 A032463 A032464 KEYWORD nonn,hard,more AUTHOR N. J. A. Sloane. EXTENSIONS a(23)-a(31) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018 a(32) from Jeppe Stig Nielsen, Apr 04 2020 STATUS approved

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Last modified July 16 10:27 EDT 2024. Contains 374345 sequences. (Running on oeis4.)