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%I #12 Mar 29 2023 04:52:59
%S 2,12,16,17,30,40,41,42,60,110,12104,12678
%N Numbers k such that 10^k + 11131719 is prime.
%C 11131719 is the concatenation of 11,13,17,19, the primes between 10 and 20, chosen because they appear on the Ishango prime bone. Notice the consecutive values of 40, 41 and 42 above. Also 10^12678+11131719 and 10^12104+11131719 are probable primes (Fermat and Lucas PRPs) that occur in this sequence.
%D Jason Earls, Red Zen, Lulu Press, NY, 2007, pp. 147-148. ISBN: 978-1-4303-2017-3.
%o (PARI) for(n=1,200,if(isprime(10^n+11131719),print1(n",")))
%K more,nonn
%O 1,1
%A _Jason Earls_, May 27 2007
%E a(11)-a(12) from _Michael S. Branicky_, Mar 27 2023
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