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A059621 Numbers k such that (5*3^k + 7)/2 is prime. 1
1, 3, 7, 9, 19, 27, 57, 69, 163, 175, 357, 379, 3045 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(14) > 30163. - Jinyuan Wang, Jan 28 2020

LINKS

Table of n, a(n) for n=1..13.

MATHEMATICA

Do[ If[ PrimeQ[ (5*3^n + 7)/2 ], Print[n] ], {n, 0, 10000} ]

PROG

(PARI) is(n)=ispseudoprime((5*3^n+7)/2) \\ Charles R Greathouse IV, Jun 13 2017

(MAGMA) [k: k in [0..1000] | IsPrime((5*3^k + 7) div 2)]; // Jinyuan Wang, Jan 28 2020

CROSSREFS

Cf. A059622 ((5*3^k-7)/2 is prime).

Sequence in context: A154508 A073573 A309328 * A034926 A224849 A304128

Adjacent sequences:  A059618 A059619 A059620 * A059622 A059623 A059624

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Feb 19 2001

STATUS

approved

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Last modified June 14 07:10 EDT 2021. Contains 345018 sequences. (Running on oeis4.)