

A058591


Numbers k such that 5*3^k  2 is prime.


1



0, 1, 2, 5, 6, 8, 11, 12, 14, 17, 26, 47, 59, 65, 83, 92, 96, 110, 113, 186, 527, 834, 1274, 5124, 5750, 7616, 11328, 54287, 57186
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

No further terms <= 55000.  Serge Batalov, Oct 31 2010
a(30) > 2*10^5.  Robert Price, May 20 2015


LINKS

Table of n, a(n) for n=1..29.


MATHEMATICA

Do[ If[ PrimeQ[ 5*3^n  2 ], Print[ n ] ], {n, 0, 4200} ]


PROG

(MAGMA) [n: n in [0..1000]  IsPrime(5*3^n2)]; // Vincenzo Librandi, May 21 2015
(PARI) is(n)=ispseudoprime(5*3^n2) \\ Charles R Greathouse IV, Jun 13 2017
(PFGW) ABC2 5*3^$a  2
a: from 0 to 10000 // Jinyuan Wang, Feb 01 2020


CROSSREFS

Cf. A058590 (5*3^k + 2 is prime).
Sequence in context: A132142 A045751 A047267 * A247062 A059009 A214642
Adjacent sequences: A058588 A058589 A058590 * A058592 A058593 A058594


KEYWORD

nonn,more


AUTHOR

Robert G. Wilson v, Dec 26 2000


EXTENSIONS

Corrected by and more PRP terms from Serge Batalov, Oct 31 2010
a(29) from Robert Price, May 20 2015
Added 0 from Vincenzo Librandi, May 21 2015


STATUS

approved



