

A093405


Primes of the form 80*R_n + 9, where R_n is the repunit (A002275) of length n.


0




OFFSET

1,1


COMMENTS

Primes of the form (8*10^n+1)/9.  Vincenzo Librandi, Jul 17 2012


LINKS

Table of n, a(n) for n=1..4.
Makoto Kamada, Prime numbers of the form 88...889.
Index entries for primes involving repunits


MATHEMATICA

Select[Table[(8*10^n+1)/9, {n, 1, 200}], PrimeQ] (* Vincenzo Librandi, Jul 17 2012


CROSSREFS

Cf. A056663 (corresponding n).
Sequence in context: A072314 A087538 A087341 * A221307 A058631 A078293
Adjacent sequences: A093402 A093403 A093404 * A093406 A093407 A093408


KEYWORD

nonn


AUTHOR

Rick L. Shepherd, Mar 28 2004


STATUS

approved



