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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
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
Sequence in context: A302844 A180630 A173079 * A154785 A090512 A076175
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.)