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 A114787 Smallest prime of the form: all fives followed by prime(n). a(n) >prime(n). 0 if no such prime exists. 0
 0, 53, 0, 557, 55511, 55555555555555555555555555555555555555555555555555555555555555555555513, 55555517, 5519, 523, 55529, 5531, 0, 541, 55555543, 547, 55555553, 55555559 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Prime(n) is all zeros followed by prime(n). This is all fives followed by prime(n). The next sequence in this progression, "Smallest prime of the form: all sixes followed by prime(n), a(n)> prime(n)", begins 0, 0, 0, 67, then (5) = 2*(10^5039 - 1)/3 - 55, a number that consists of 5037 sixes followed by 2 ones. This does not fit into the constraints of the OEIS. N. J. A. Sloane, Nov 20 2005, based on information from Hans Havermann. The large number is quickly certified prime by PARI's APRCL test: isprime(555...513,2) -> 1. - Hagen von Eitzen, Jun 17 2009 Next term is 5*(10^184 - 1)/9 + 6, containing 184 digits, and is too large to include here. - Arkadiusz Wesolowski, Jun 03 2013 LINKS EXAMPLE a(5) = 55511, as 511, 5511 are composite, prime(5) = 11. All positive numbers of the form 5*(10^k - 1)/9 - 18 have a factor in the covering set {3, 7, 13, 37}, so a(12) = 0. - Arkadiusz Wesolowski, Jun 03 2013 CROSSREFS Cf. A114783, A114784, A114785, A114786. Sequence in context: A208300 A038778 A116107 * A198776 A051320 A232126 Adjacent sequences:  A114784 A114785 A114786 * A114788 A114789 A114790 KEYWORD base,nonn AUTHOR Amarnath Murthy, Nov 17 2005 EXTENSIONS More terms from Joshua Zucker, May 06 2006 Edited by T. D. Noe, Oct 30 2008 a(12)-a(17) from Arkadiusz Wesolowski, Jun 03 2013 STATUS approved

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Last modified October 22 07:48 EDT 2019. Contains 328315 sequences. (Running on oeis4.)