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 A059801 Numbers k such that 4^k - 3^k is prime. 120
 2, 3, 7, 17, 59, 283, 311, 383, 499, 521, 541, 599, 1193, 1993, 2671, 7547, 24019, 46301, 48121, 68597, 91283, 131497, 148663, 184463, 341233 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Some of the larger entries may only correspond to probable primes. The values corresponding to 1193 (719 digits) and 1993 (1200 digits) have been certified prime with Primo. - Rick L. Shepherd, Sep 10 2002 8 more terms found by Jean-Louis Charton during 2004 - 2006. Corresponding numbers of decimal digits are 14461, 27876, 28972, 41300, 54958, 79170, 89505, 111058, 205443. - Alexander Adamchuk, Dec 02 2006 LINKS Bogley, William A.; Williams, Gerald Efficient finite groups arising in the study of relative asphericity. Math. Z. 284, No. 1-2, 507-535 (2016). MATHEMATICA Select[Range[1000], PrimeQ[4^# - 3^#] &] (* Alonso del Arte, Nov 03 2011 *) PROG (PARI) select(vector(10^5, i, i), n->ispseudoprime(4^n-3^n)) \\ Charles R Greathouse IV, Feb 11 2011 CROSSREFS Cf. A000043, A057468, A059802, etc., A129736, A129737. Sequence in context: A176074 A281368 A330726 * A102226 A195530 A295509 Adjacent sequences: A059798 A059799 A059800 * A059802 A059803 A059804 KEYWORD nonn,nice,hard AUTHOR Mike Oakes, Feb 23 2001 STATUS approved

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Last modified March 28 03:48 EDT 2023. Contains 361577 sequences. (Running on oeis4.)