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 A055625 First prime starting a chain of exactly n consecutive primes congruent to 1 modulo 6. 5
 7, 31, 151, 3049, 7351, 1741, 19471, 118801, 498259, 148531, 406951, 2513803, 2339041, 89089369, 51662593, 73451737, 232301497, 450988159, 1558562197, 2506152301, 1444257673, 28265029657, 24061965043, 87996684091, 43553959717 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The term "exactly" means that before the first and after the last primes of chain, the immediate primes are not congruent to 1 modulo 6. See A057620 for the variant where "exactly" is replaced by "at least". - M. F. Hasler, Sep 03 2016 LINKS Giovanni Resta, Table of n, a(n) for n = 1..35 (terms < 4*10^14) J. K. Andersen, Consecutive Congruent Primes. A. Granville and G. Martin, Prime number races, Amer. Math. Monthly, 113 (No. 1, 2006), 1-33. MATHEMATICA pp = Table[{p = Prime[n], Mod[p, 6]}, {n, 10^6}]; sp = Split[pp, Mod[#1[[2]], 6] == Mod[#2[[2]], 6]&]; a[n_] := SelectFirst[sp, Length[#] == n && MatchQ[#, {{_Integer, 1} ..}]& ][[1, 1]]; Table[an = a[n]; Print[n, " ", an]; an, {n, 1, 13}] (* Jean-François Alcover, Nov 21 2018 *) PROG See link in A085515. CROSSREFS Cf. A055623, A055624, A055626, A085515. Sequence in context: A121517 A199216 A057620 * A102239 A188233 A319457 Adjacent sequences:  A055622 A055623 A055624 * A055626 A055627 A055628 KEYWORD nonn AUTHOR Labos Elemer, Jun 05 2000 EXTENSIONS Corrected and extended by Reiner Martin (reinermartin(AT)hotmail.com), May 19 2001 More terms from Hugo Pfoertner, Jul 31 2003 a(20)>2^31, a(21)=1444257673. - Hugo Pfoertner, Jul 31 2003 More terms from Jens Kruse Andersen, May 30 2006 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 27 2006 STATUS approved

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Last modified May 7 16:00 EDT 2021. Contains 343652 sequences. (Running on oeis4.)