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%I #3 Dec 15 2017 17:37:04
%S 11,29,67,179,113,53,193,143,103,173,793,181,43,263,601,839,13,331,
%T 179,167,841,59,557,359,2437,139,113,317,109,389,551,3517,757,187,
%U 1327,829,401,523,811,487,563,1909,473,703,583,2131,1751
%N Least positive k such that Z(n) + k is prime, where Z(n) = 1357986420*(10^(10*n)-1)/(10^10-1).
%C The majority of the decimal expansions of these (probable) primes have the pattern 13579864201357986420..., e.g. a(3)=67 and Z(3) + 67 = 135798642013579864201357986487. a(1001)=4637. Proof: PFGW Version 1.2.0 for Windows [FFT v23.8] Primality testing 1357986420*(10^(10*1001)-1)/(10^10-1)+4637 [N-1/N+1, Brillhart-Lehmer-Selfridge] Running N-1 test using base 3 Running N+1 test using discriminant 7, base 1+sqrt(7) Running N+1 test using discriminant 7, base 2+sqrt(7) 1357986420*(10^(10*1001)-1)/(10^10-1)+4637 is Fermat and Lucas PRP!
%K nonn,less
%O 1,1
%A _Jason Earls_, Aug 19 2006
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