login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093405 Primes of the form 80*R_n + 9, where R_n is the repunit (A002275) of length n. 0
89, 88888888888889, 88888888888888889, 88888888888888888888888888888888889 (list; graph; refs; listen; history; text; internal format)
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

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 February 21 02:02 EST 2020. Contains 332086 sequences. (Running on oeis4.)