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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108328 Integers n such that 10^n - 23 is a prime number. 16
3, 11, 17, 23, 35, 161, 765, 3473, 6887, 27681, 34313 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No additional terms < 40000. - Robert Price, Dec 13 2010

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99977".

No other terms < 100,000. - Robert Price, Mar 03 2011

LINKS

Table of n, a(n) for n=1..11.

Makoto Kamada, List of near-repdigit-related prime numbers.

Index entries for primes involving repunits.

EXAMPLE

n = 3 is a member because 10^3 - 23 = 1000 - 23 = 977, which is prime.

MATHEMATICA

lst={}; Do[If[PrimeQ[10^n-23], AppendTo[lst, n]], {n, 0, 10^4}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 19 2008 *)

CROSSREFS

Cf. A089675, A095714, A092767.

Sequence in context: A165561 A038960 A019397 * A153419 A079020 A118590

Adjacent sequences:  A108325 A108326 A108327 * A108329 A108330 A108331

KEYWORD

more,nonn

AUTHOR

Julien Peter Benney (jpbenney(AT)ftml.net), Jun 30 2005

EXTENSIONS

a(9)-a(11) from Robert Price, Dec 13 2010

Edited by Ray Chandler, Dec 23 2010

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.