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 A136721 Prime quadruples: 3rd term. 2
 11, 17, 107, 197, 827, 1487, 1877, 2087, 3257, 3467, 5657, 9437, 13007, 15647, 15737, 16067, 18047, 18917, 19427, 21017, 22277, 25307, 31727, 34847, 43787, 51347, 55337, 62987, 67217, 69497, 72227, 77267, 79697, 81047, 82727, 88817, 97847 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p such that p-6, p-4, and p+2 are prime. Apart from the first term, a(n) = 17 (mod 30). The members of each quadruple are twin primes when they are 1st and 2nd terms and when 3rd and 4th terms. When they are 2nd and 3rd terms they differ by 4. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A007530(n)+6 = A136720(n)+4 = A090258(n)-2. - Robert Israel, Oct 11 2019 EXAMPLE The four terms in the first quadruple are 5,7,11,13 and in the 2nd 11,13,17,19. The four terms or members of each set must be simultaneously prime. MAPLE p2:= 0: p3:= 0: p4:= 0: Res:= NULL: count:= 0: while count < 100 do   p1:= p2; p2:= p3; p3:= p4;   p4:= nextprime(p4);   if [p2-p1, p3-p2, p4-p3] = [2, 4, 2] then      count:= count+1; Res:= Res, p3   fi od: Res; # Robert Israel, Oct 11 2019 MATHEMATICA lst={}; Do[p0=Prime[n]; If[PrimeQ[p2=p0+2], If[PrimeQ[p6=p0+6], If[PrimeQ[p8=p0+8], AppendTo[lst, p6]]]], {n, 12^4}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 22 2008 *) CROSSREFS Cf. A007530, A090258, A136720. Sequence in context: A250716 A244853 A102870 * A107172 A090286 A226677 Adjacent sequences:  A136718 A136719 A136720 * A136722 A136723 A136724 KEYWORD easy,nonn AUTHOR Enoch Haga, Jan 18 2008 EXTENSIONS Edited by Charles R Greathouse IV, Oct 11 2009 STATUS approved

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Last modified April 16 03:37 EDT 2021. Contains 343030 sequences. (Running on oeis4.)