|
| |
|
|
A093405
|
|
Primes of the form 80*R_k + 9, where R_k is the repunit (A002275) of length k.
|
|
0
|
| |
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
Primes of the form (8*10^k + 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 k).
Sequence in context: A072314 A087538 A087341 * A348166 A221307 A058631
Adjacent sequences: A093402 A093403 A093404 * A093406 A093407 A093408
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Rick L. Shepherd, Mar 28 2004
|
|
|
STATUS
|
approved
|
| |
|
|
