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 A145993 Primes that start a run of at least 2 consecutive primes of the form 4k+3. 5
 7, 19, 43, 67, 79, 103, 127, 163, 199, 307, 359, 379, 439, 463, 619, 643, 683, 719, 739, 823, 859, 883, 967, 983, 1087, 1163, 1279, 1303, 1423, 1439, 1459, 1483, 1499, 1559, 1663, 1783, 1811, 1867, 1979, 1999, 2083, 2099, 2179, 2239, 2347, 2399, 2447, 2531, 2579, 2659, 2683, 2699, 2803, 2843, 2879 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES Enoch Haga, Exploring Primes on Your PC and the Internet, 1994-2007. Pp. 30-31. ISBN 978-1-885794-24-6 LINKS EXAMPLE a(1)=7 because this sequence includes consecutive runs of any length and this first term >1 in a run of 2 is 7. MAPLE A145993 := proc()     local m, p, r, i, sp ;     m := 3 ;     p := 2 ;     r := 0 ;     sp := -1 ;     for i from 2 to 1000 do         if modp(p, 4) = m then             r := r+1 ;             if r = 1 then                 sp := p ;             end if;         else             if r > 1 then                 printf("%d, ", sp) ;             end if;             r := 0;             sp := -1 ;         end if;         p := nextprime(p) ;     end do: end proc: A145993() ; # R. J. Mathar, Aug 29 2018 MATHEMATICA Most[First /@ Select[ SplitBy[ Prime@ Range@ 425, Mod[#, 4] &], Mod[#[[1]], 4] == 3 && Length[#] > 1 &]] (* Giovanni Resta, Aug 29 2018 *) CROSSREFS Cf. A039702, A055623, A145986, A145988, A145989, A145990, A145991, A145992 (run lengths) A145994. Sequence in context: A192755 A141193 A104163 * A265676 A054690 A259486 Adjacent sequences:  A145990 A145991 A145992 * A145994 A145995 A145996 KEYWORD easy,nonn AUTHOR Enoch Haga, Oct 26 2008 EXTENSIONS 619 inserted by R. J. Mathar, Aug 29 2018 STATUS approved

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Last modified June 20 12:34 EDT 2021. Contains 345164 sequences. (Running on oeis4.)