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 A123372 Numbers n such that 10*(11*10^n - 1) + 1 is prime. 0
 0, 1, 29, 71, 95, 173, 298, 4937, 4982, 15755, 16639, 17621 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Table of n, a(n) for n=1..12. EXAMPLE a(1) = 0; 101 is prime. a(2) = 1; 1091 is prime. a(3) = 29; 10999999999999999999999999999991 is prime. MATHEMATICA Select[Range[0, 1000], PrimeQ[10*(11*10^#-1)+1]&] PROG (PARI) g(n, m=1) = for(x=1, n, y=10*(11*10^x-1)+m; if(ispseudoprime(y), print1(x", "))) CROSSREFS Sequence in context: A165945 A226892 A183194 * A031343 A155483 A141891 Adjacent sequences: A123369 A123370 A123371 * A123373 A123374 A123375 KEYWORD hard,more,nonn AUTHOR Cino Hilliard, Oct 12 2006 EXTENSIONS 0 inserted and a(10)-a(12) from Ryan Hitchman, Sep 13 2017 STATUS approved

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Last modified May 25 17:00 EDT 2024. Contains 372804 sequences. (Running on oeis4.)