A135132 Integers n such that 10^n + 73 is a prime number.

1, 2, 8, 11, 145, 695, 1099, 3518, 6211, 13015

Offset: 1

Author

Julien Peter Benney (jpbenney(AT)gmail.com), Feb 12 2008

Keywords

• more
• nonn

Comments

a(5) to a(7) were certified prime with PRIMO. - Bernardo Boncompagni, Nov 07 2008

The next term (if one exists) is > 100000. - Robert Price, Apr 25 2011

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "10073".

Examples

			8 is a member because 10^8+73 = 100000000+73 = 100000073, which is prime.
		

Links

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

Crossrefs

Cf. A095688, A108052, A108050, A108312, A107083, A108049, A108054.

Programs

Mathematica

Select[Range[1000], PrimeQ[10^# + 73] &] (* G. C. Greubel, Sep 28 2016 *)

Extensions

a(7) from Bernardo Boncompagni, Nov 07 2008

Added term 13015. Robert Price, Mar 22 2010

Added two terms: 3518,6211. Robert Price, Oct 10 2010

Edited by Ray Chandler, Dec 23 2010