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 A032390 Numbers k such that 81*2^k+1 is prime. 1
 1, 4, 5, 7, 12, 15, 16, 21, 25, 27, 32, 35, 36, 39, 48, 89, 104, 121, 125, 148, 152, 267, 271, 277, 296, 324, 344, 396, 421, 436, 447, 539, 577, 592, 711, 809, 852, 1384, 1972, 2624, 2829, 3497, 3945, 3995, 4911, 5225, 5676, 5811, 7025, 7671, 8512, 10399 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Joerg Arndt, Table of n, a(n) for n = 1..81 (from http://www.prothsearch.com/riesel1.html) 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 PROG (PARI) is(n)=ispseudoprime(81*2^n+1) \\ Charles R Greathouse IV, Jun 07 2017 CROSSREFS Sequence in context: A064401 A079337 A160934 * A372631 A112918 A138920 Adjacent sequences: A032387 A032388 A032389 * A032391 A032392 A032393 KEYWORD nonn AUTHOR James R. Buddenhagen STATUS approved

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Last modified September 8 01:34 EDT 2024. Contains 375749 sequences. (Running on oeis4.)