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 A173903 Numbers k such that both (2^k+1)^2-2 and (2^k-1)^2-2 are prime. 0
 2, 3, 12, 15, 18, 21, 27 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(8) > 9394. - Max Z. Scialabba, Jan 21 2024 LINKS Table of n, a(n) for n=1..7. FORMULA A091513 INTERSECT A091515. - R. J. Mathar, Jul 06 2010 MATHEMATICA Select[Range[3000], PrimeQ[((2^# + 1)^2 - 2)]&&PrimeQ[((2^# - 1)^2 - 2)] &] (* Vincenzo Librandi, Aug 21 2014 *) PROG (Magma) [n: n in [1..400] | IsPrime((2^n-1)^2-2) and IsPrime((2^n+1)^2-2)] CROSSREFS Cf. A091513, A091515. Sequence in context: A302844 A180630 A173079 * A154785 A090512 A076175 Adjacent sequences: A173900 A173901 A173902 * A173904 A173905 A173906 KEYWORD nonn,hard,more AUTHOR Vincenzo Librandi, Mar 08 2010 EXTENSIONS Definition clarified by Jon E. Schoenfield, Jun 18 2010 STATUS approved

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Last modified July 12 06:35 EDT 2024. Contains 374237 sequences. (Running on oeis4.)