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 A194607 Record values in A194606. 12
 0, 1, 2, 4, 5, 6, 11, 17, 20, 28, 70, 99, 150, 726, 7431, 22394, 85461, 191207 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The index sequence of this one is 1, 3, 6, 15, 17, 29, 53, 115, 186, 220, 229, 1886, 5344, 5736, 66774, 1087403, 14747671, 158018119. a(17) was found in 2000 by Wilfrid Keller and a(18) was found in 2003 by Patrick De Geest. REFERENCES Wilfrid Keller, personal communication, 2010. LINKS Chris K. Caldwell, The List of Largest Known Primes, 270704167 * 2^85461 - 1 Chris K. Caldwell, The List of Largest Known Primes, 3296757029 * 2^191207 + 1 Carlos Rivera, Problem 30 EXAMPLE A194606(53) = 11 since A194606(115) = 17 is the next record value. MATHEMATICA l = -1; Flatten[Table[p = Prime[n]; k = 0; While[! PrimeQ[p*2^k - 1] && ! PrimeQ[p*2^k + 1], k++]; If[k > l, l = k, {}], {n, 10^4}]] (* Arkadiusz Wesolowski, Sep 04 2011 *) CROSSREFS Cf. A194591, A194600, A194603, A194606, A194608, A194635, A194636, A194637, A194638, A194639. Cf. A103963, A103964, A076335, A180247. Sequence in context: A192582 A101951 A171166 * A194637 A194600 A255543 Adjacent sequences:  A194604 A194605 A194606 * A194608 A194609 A194610 KEYWORD more,nonn AUTHOR Arkadiusz Wesolowski, Aug 30 2011 STATUS approved

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Last modified February 16 16:00 EST 2020. Contains 331961 sequences. (Running on oeis4.)