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 A104138 Smallest prime followed by n or more composites. 4
 2, 3, 7, 7, 23, 23, 89, 89, 113, 113, 113, 113, 113, 113, 523, 523, 523, 523, 887, 887, 1129, 1129, 1327, 1327, 1327, 1327, 1327, 1327, 1327, 1327, 1327, 1327, 1327, 1327, 9551, 9551, 15683, 15683, 15683, 15683, 15683, 15683, 15683, 15683, 19609 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Except for a(1), records occur at even values of n, and each term appears an even number of times consecutively. (Proof. A maximal run of composites must begin and end at even numbers.) - Jonathan Sondow, May 31 2014 LINKS Charles R Greathouse IV, Table of n, a(n) for n = 0..1000 FORMULA Record prime A002386(n+1) appears A053695(n-1) times, for n>1. a(n) = A030296(n) - 1, for n > 0. - Jonathan Sondow, May 31 2014 EXAMPLE a(10)=113 because it is the first prime occurring before primes 199,211,293,317,467,509,... all followed by at least ten successive composites. CROSSREFS Cf. A002386, A005250, A030296, A053695. Sequence in context: A085420 A027672 A322138 * A281909 A083809 A092967 Adjacent sequences: A104135 A104136 A104137 * A104139 A104140 A104141 KEYWORD nonn AUTHOR Lekraj Beedassy, Mar 07 2005 EXTENSIONS a(34) corrected by Charles R Greathouse IV, Aug 09 2011 STATUS approved

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Last modified June 1 17:00 EDT 2023. Contains 363076 sequences. (Running on oeis4.)