A108326 Integers n such that 10^n-17 is prime.

2, 3, 6, 30, 40, 86, 128, 264, 639, 912, 1932, 4650, 5038, 7410, 19041

Offset

1,1

Comments

Terms 639 and 912 correspond to certified primes (Primo 2.2.0 beta). - Ryan Propper, Jul 12 2005

No other terms < 40000.

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99983".

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

Links

Table of n, a(n) for n=1..15.

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

Index entries for primes involving repunits.

Example

If n = 3 we have 10^3-17 = 1000-17 = 983, which is prime.

Crossrefs

Cf. A089675, A095714, A092767.

Sequence in context: A051717 A330030 A192441 * A002234 A074005 A145499

Adjacent sequences: A108323 A108324 A108325 * A108327 A108328 A108329

Keyword

more,nonn

Author

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

Extensions

a(14)-a(15) from Robert Price, Dec 11 2010

Edited by Ray Chandler, Dec 23 2010

Status

approved