login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
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: A137093 A080626 A015957 * A074417 A296105 A268120

Adjacent sequences:  A268353 A268354 A268355 * A268357 A268358 A268359

KEYWORD

nonn,more

AUTHOR

Robert Price, Feb 02 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 21 06:54 EDT 2019. Contains 326162 sequences. (Running on oeis4.)