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 A136720 Prime quadruples: 2nd term. 2
 7, 13, 103, 193, 823, 1483, 1873, 2083, 3253, 3463, 5653, 9433, 13003, 15643, 15733, 16063, 18043, 18913, 19423, 21013, 22273, 25303, 31723, 34843, 43783, 51343, 55333, 62983, 67213, 69493, 72223, 77263, 79693, 81043, 82723, 88813, 97843 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p such that p-2, p+4, and p+6 are prime. Apart from the first term, a(n) = 13 (mod 30). LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A007530(n)+2 = A136721(n)-4 = A090258(n)-6. - 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, p2   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, p2]]]], {n, 12^4}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 22 2008 *) CROSSREFS Cf. A007530, A090258, A136721. Sequence in context: A039687 A001544 A202152 * A323468 A035030 A046519 Adjacent sequences:  A136717 A136718 A136719 * A136721 A136722 A136723 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 05:20 EDT 2021. Contains 343030 sequences. (Running on oeis4.)