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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. 10
 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 FORMULA From Wesley Ivan Hurt, May 03 2022: (Start) a(n) = A132929(n) - 1. a(n) = A177336(n) - 2. (End) 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. Cf. A132929, A177336. Sequence in context: A106914 A337924 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 April 21 09:27 EDT 2024. Contains 371851 sequences. (Running on oeis4.)