A108331 Integers k such that 10^k - 87 is prime.

2, 1800, 2368, 15328

Offset: 1

Author

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

Keywords

• more
• nonn

Comments

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99913".

a(5) > 10^5. - Tyler NeSmith, Jul 26 2021

Examples

			k = 2 is a term because 10^2 - 87 = 100 - 87 = 13, which is prime.
		

Links

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

Crossrefs

Cf. A089675, A095714, A092767.

Extensions

a(4) from Kamada data by Robert Price, Dec 13 2010

Edited by Ray Chandler, Dec 23 2010