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A110918 Integers n such that 10^n+91 is a prime number. 2
1, 2, 3, 4, 11, 12, 15, 19, 136, 144, 732, 5774, 6602, 23499, 39583, 74254, 93356, 94016 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

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".

LINKS

Table of n, a(n) for n=1..18.

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

Index entries for primes involving repunits.

EXAMPLE

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

MATHEMATICA

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

PROG

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

CROSSREFS

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

Sequence in context: A084544 A268236 A039023 * A181542 A160914 A155768

Adjacent sequences:  A110915 A110916 A110917 * A110919 A110920 A110921

KEYWORD

more,nonn

AUTHOR

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

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

STATUS

approved

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Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.