A268356 - OEIS

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A268356

Numbers n such that 8*9^n - 1 is prime.

3

0, 1, 2, 5, 25, 85, 92, 97, 649, 2017, 2978, 3577, 4985, 17978, 21365, 66002, 95305, 142199

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OFFSET

1,3

COMMENTS

a(19) > 2*10^5.

LINKS

Table of n, a(n) for n=1..18.

MATHEMATICA

Select[Range[0, 200000], PrimeQ[8*9^# - 1] &] (* Robert Price, Feb 02 2016 *)

PROG

(PARI) is(n)=ispseudoprime(8*9^n-1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A056799, A198966.

Sequence in context: A080626 A015957 A349146 * A329158 A337435 A074417

Adjacent sequences: A268353 A268354 A268355 * A268357 A268358 A268359

KEYWORD

nonn,more

AUTHOR

Robert Price, Feb 02 2016

STATUS

approved