A108328 Integers n such that 10^n - 23 is a prime number.

3, 11, 17, 23, 35, 161, 765, 3473, 6887, 27681, 34313

Offset: 1

Author

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

Keywords

• more
• nonn

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

Examples

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

Links

• Makoto Kamada, List of near-repdigit-related prime numbers.
• Index entries for primes involving repunits.

Crossrefs

Cf. A089675, A095714, A092767.

Programs

Mathematica

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

Extensions

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

Edited by Ray Chandler, Dec 23 2010