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 A096254 Numbers n such that 5*10^n + 3 is prime. 2
 1, 2, 3, 8, 18, 20, 31, 42, 103, 175, 181, 531, 706, 1077, 1177, 1552, 19737, 32197, 51508, 58275, 62233, 90033 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(23) > 2*10^5. - Robert Price, Aug 03 2015 LINKS Makoto Kamada, Prime numbers of the form 500...003. Sabin Tabirca and Kieran Reynolds, Lacunary Prime Numbers. FORMULA a(n) = A101568(n) + 1. EXAMPLE 1, 2 and 3 are in the list because 53, 503 and 5003 are all prime. 500000003 (5*10^8 + 3) is the next similar prime, so 8 is the next term in the sequence. MATHEMATICA Do[ If[ PrimeQ[5*10^n + 3], Print[n]], {n, 10000}] (* Robert G. Wilson v, Aug 13 2004 *) PROG (PARI) is(n)=isprime(5*10^n+3) \\ Charles R Greathouse IV, Sep 27 2016 CROSSREFS Cf. A101568. Sequence in context: A101182 A009207 A290878 * A091765 A036746 A232165 Adjacent sequences:  A096251 A096252 A096253 * A096255 A096256 A096257 KEYWORD more,nonn AUTHOR Carl R. White, Aug 10 2004 EXTENSIONS a(12)-a(16) from Robert G. Wilson v, Aug 13 2004 a(17)-a(22) from Kamada data by Robert Price, Dec 09 2010 STATUS approved

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Last modified February 26 08:33 EST 2020. Contains 332277 sequences. (Running on oeis4.)