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

2, 1800, 2368, 15328

Offset

1,1

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

Links

Table of n, a(n) for n=1..4.

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

Index entries for primes involving repunits.

Example

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

Crossrefs

Cf. A089675, A095714, A092767.

Sequence in context: A277389 A011541 A080642 * A263076 A162554 A167840

Adjacent sequences: A108328 A108329 A108330 * A108332 A108333 A108334

Keyword

more,nonn

Author

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

Extensions

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

Edited by Ray Chandler, Dec 23 2010

Status

approved