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 A323043 Numbers k such that 397*2^k+1 is prime. 0
 4, 6, 16, 24, 30, 36, 40, 52, 60, 78, 132, 204, 352, 556, 1936, 4876, 5278, 6450, 6546, 9498, 10878, 13012, 22356, 24498, 28768, 29952, 41050, 46242, 56874, 61414, 74148, 81306, 118090, 134056, 391200, 598342, 825972, 1293028, 2598796 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..39. Ray Ballinger, Proth Search Page Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for 300 < k < 600 Y. Gallot, Proth.exe: Windows Program for Finding Large Primes Wilfrid Keller, List of primes k.2^n - 1 for k < 300 Eric Weisstein's World of Mathematics, Proth Prime Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime MATHEMATICA Select[Range[1000], PrimeQ[397*2^# + 1] &] (* Robert Price, Jan 03 2019 *) CROSSREFS Sequence in context: A306905 A097970 A044858 * A120375 A025618 A133572 Adjacent sequences: A323040 A323041 A323042 * A323044 A323045 A323046 KEYWORD nonn,more,hard AUTHOR Robert Price, Jan 03 2019 EXTENSIONS a(39) from Jeppe Stig Nielsen, Jan 04 2020 STATUS approved

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Last modified June 17 10:05 EDT 2024. Contains 373445 sequences. (Running on oeis4.)