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A059528 Numbers k such that (7*3^k + 5)/2 is prime. 1
1, 3, 5, 15, 21, 27, 65, 191, 327, 371, 575, 1895, 2375, 2607, 9735 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(16) > 20055. - Jinyuan Wang, Jan 29 2020
LINKS
MATHEMATICA
Do[ If[ PrimeQ[ (7*3^n + 5)/2 ], Print[n] ], {n, 0, 5300} ]
PROG
(PARI) is(n)=ispseudoprime((7*3^n+5)/2) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
Cf. A059569 ((7*3^k-5)/2 is prime).
Sequence in context: A208854 A165260 A201874 * A070079 A142717 A057742
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Feb 16 2001
EXTENSIONS
a(15) from Jinyuan Wang, Jan 29 2020
STATUS
approved

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Last modified February 24 20:59 EST 2024. Contains 370307 sequences. (Running on oeis4.)