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Integers n such that 10^n+99 is prime.
4

%I #31 Sep 08 2022 08:45:20

%S 1,2,4,6,13,14,16,17,19,30,31,60,68,73,113,144,276,288,364,449,473,

%T 739,833,1171,1732,2292,3912,7673,9458,16982,19751,21479,23837,77726

%N Integers n such that 10^n+99 is prime.

%C The next term, if one exists, is >100000. - _Robert Price_, Apr 25 2011

%C See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "10w99".

%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/">List of near-repdigit-related prime numbers</a>.

%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.

%e If n=6, we have 10^6+99 = 1000000+99 = 1000099, which is prime.

%t Select[Range[78000],PrimeQ[10^#+99]&] (* _Harvey P. Dale_, Aug 23 2013 *)

%o (Magma) [n: n in [1..400]| IsPrime(10^n+99)]; // _Vincenzo Librandi_, Nov 02 2014

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

%K more,nonn

%O 1,2

%A Julien Peter Benney (jpbenney(AT)ftml.net), Sep 30 2005

%E a(1)=1 added by _Vladimir Joseph Stephan Orlovsky_, May 02 2008

%E a(29)-a(33) from _Robert Price_, Mar 22 2010

%E a(34)=77726 from _Robert Price_, Mar 03 2011