A110918 Integers n such that 10^n+91 is a prime number.

1, 2, 3, 4, 11, 12, 15, 19, 136, 144, 732, 5754, 6602, 23499, 39583, 74254, 93356, 94016

Offset: 1

Author

Julien Peter Benney (jpbenney(AT)ftml.net), Oct 04 2005

Keywords

• more
• nonn

Comments

No additional terms < 100000.

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "10091".

Examples

			n = 4 is a member: 10^4+91 = 10000+91 = 10091, which is prime.
		

Links

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

Crossrefs

Cf. A049054, A088274, A088275, A095688, A107083, A108049, A108050, A108052, A108054.

Programs

Magma

[n: n in [1..400]| IsPrime(10^n+91)]; // Vincenzo Librandi, Nov 02 2014

Mathematica

Select[Range[2000], PrimeQ[10^# + 91] &] (* Vincenzo Librandi, Nov 02 2014 *)

Extensions

a(1)=1 added by Vladimir Joseph Stephan Orlovsky, May 02 2008

a(12)-a(15) from Robert Price, Dec 12 2010

Edited by Ray Chandler, Dec 23 2010

a(16)=74254 from Robert Price, Mar 03 2011

a(17)=92178 and a(18)=94016 from Robert Price, Apr 19 2011

a(17)=93356 corrected by Robert Price, Apr 19 2011

a(12) corrected by Tyler Busby, May 03 2024