

A056799


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


6



1, 4, 5, 11, 26, 29, 38, 65, 166, 490, 641, 2300, 9440, 44741, 65296, 161930
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OFFSET

1,2


COMMENTS

a(17)>2*10^5.  Robert Price, Feb 22 2016
The even members of A005538, halved.  Jeppe Stig Nielsen, Oct 13 2019


LINKS

Table of n, a(n) for n=1..16.


MATHEMATICA

Do[If[PrimeQ[8*9^n + 1], Print[n]], {n, 0, 1000}]
Select[Range[3000], PrimeQ[8 9^# + 1] &] (* Vincenzo Librandi, Sep 28 2012 *)


PROG

(PARI) is(n)=ispseudoprime(8*9^n+1) \\ Charles R Greathouse IV, Mar 01 2017


CROSSREFS

Cf. A005538.
Sequence in context: A000769 A246495 A050831 * A216963 A259821 A109503
Adjacent sequences: A056796 A056797 A056798 * A056800 A056801 A056802


KEYWORD

nonn


AUTHOR

Robert G. Wilson v, Aug 22 2000


EXTENSIONS

a(12) from Vincenzo Librandi, Sep 28 2012
a(13)a(16) from Robert Price, Feb 22 2016


STATUS

approved



