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 A174920 List of primes p1 such that (p1,p2) are twin primes where both 2*p1+p2 and p1+2*p2 are primes. 7
 3, 5, 59, 269, 1949, 2999, 6359, 11489, 11549, 14549, 18539, 19889, 21839, 31079, 32909, 32969, 33329, 33599, 42569, 42839, 50459, 53549, 58109, 68879, 70199, 74609, 79229, 80909, 93809, 96329, 98909, 104309, 109139, 114599, 121019, 125789 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Terms >5 are congruent to 29 mod 30. - Zak Seidov, May 10 2012 Also 2*p1+p2 and p1+2*p2 are twin primes. - Zak Seidov, May 10 2012 LINKS Zak Seidov, Table of n, a(n) for n = 1..1000 EXAMPLE a(1)=3 because 3, 5 are twin primes and 2*3+5=11, 3+2*5=13 are also primes. MAPLE select(q -> isprime(q) and isprime(q+2) and isprime(3*q+2) and isprime(3*q+4), [3, 5, seq(i, i=29..200000, 30)]); # Robert Israel, May 06 2019 MATHEMATICA lst={}; Do[p1=Prime[n]; p2=p1+2; If[PrimeQ[p2]&&PrimeQ[2*p1+p2]&&PrimeQ[p1+2*p2], AppendTo[lst, p1]], {n, 8!}]; lst PROG (MAGMA) [NthPrime(n): n in [1..12000] | forall{p: p in [NthPrime(n)+2, 3*NthPrime(n)+2, 3*NthPrime(n)+4] | IsPrime(p)}]; // Bruno Berselli, May 10 2012 CROSSREFS Cf. A001359, A174913, A174915, A174916, A174917, A177335. Sequence in context: A155121 A106914 A049190 * A158314 A249011 A261533 Adjacent sequences:  A174917 A174918 A174919 * A174921 A174922 A174923 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Apr 02 2010 STATUS approved

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Last modified August 11 09:29 EDT 2020. Contains 336422 sequences. (Running on oeis4.)