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 A219461 Primes p such that 2^p - 1 is a prime with primitive root 3. 0
 3, 5, 7, 17, 19, 89, 107, 521 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If A096393(n) = 3, then A000043(n) belongs to this sequence. 2^a(n) - 1 is in A001123. The first term that is unknown is a(9), which is either 2203 or 2281. LINKS Discussion titled Conjecture about multiplicative order of 3 modulo a Mersenne prime, (postings in mersenneforum.org), starting May 14 2006. MATHEMATICA Select[Prime@Range[98], PrimitiveRoot[2^# - 1] == 3 &] CROSSREFS Subsequence of A000043. Sequence in context: A331800 A062547 A125739 * A122853 A137258 A053341 Adjacent sequences:  A219458 A219459 A219460 * A219462 A219463 A219464 KEYWORD hard,more,nonn AUTHOR Arkadiusz Wesolowski, Nov 20 2012 STATUS approved

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Last modified November 29 18:41 EST 2021. Contains 349416 sequences. (Running on oeis4.)