

A143279


Numbers n such that 6*5^n + 1 is prime.


3



0, 1, 2, 3, 23, 27, 33, 63, 158, 278, 290, 351, 471, 797, 8462, 28793, 266030
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OFFSET

1,3


COMMENTS

Primes found and proved by PrimeForm.
All terms correspond to verified primes, that is, not merely probable primes.  Robert Price, Jan 16 2015
a(18) > 3*10^5.  Robert Price, Jan 16 2015


LINKS

Table of n, a(n) for n=1..17.


MATHEMATICA

Select[Range[0, 10000], PrimeQ[6*5^# + 1] &] (* Robert Price, Jan 16 2015 *)


PROG

(PARI) is(n)=ispseudoprime(6*5^n+1) \\ Charles R Greathouse IV, Jun 06 2017


CROSSREFS

Sequence in context: A085946 A280894 A042585 * A272271 A068887 A260128
Adjacent sequences: A143276 A143277 A143278 * A143280 A143281 A143282


KEYWORD

hard,nonn


AUTHOR

Rick L. Shepherd, Aug 04 2008


EXTENSIONS

a(17) from Robert Price, Jan 16 2015


STATUS

approved



