# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a093166 Showing 1-1 of 1 %I A093166 #21 Jul 08 2021 05:53:25 %S A093166 3,83,883,88883,88888883,888888883,888888888888883, %T A093166 888888888888888888888888888888888888888888888888883, %U A093166 88888888888888888888888888888888888888888888888888888888888888888888883 %N A093166 Primes of the form 80*R_k + 3, where R_k is the repunit (A002275) of length k. %C A093166 Primes of the form (8*10^k - 53)/9. - _Vincenzo Librandi_, Nov 16 2010 %H A093166 Makoto Kamada, Prime numbers of the form 88...883. %H A093166 Index entries for primes involving repunits %t A093166 Select[Table[FromDigits[PadLeft[{3},n,8]],{n,80}],PrimeQ] (* _Harvey P. Dale_, Sep 21 2013 *) %Y A093166 Cf. A002275, A056694 (corresponding k), A099422. %K A093166 nonn %O A093166 1,1 %A A093166 _Rick L. Shepherd_, Mar 26 2004 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE