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A174915
Numbers p such that p, q=p+2 and p+2*q are all primes.
8
3, 5, 11, 41, 59, 101, 179, 191, 269, 311, 431, 521, 599, 821, 881, 1019, 1061, 1151, 1229, 1301, 1451, 1481, 1619, 1721, 1949, 2081, 2111, 2141, 2729, 2999, 3299, 3821, 4001, 4091, 4259, 4421, 4799, 4931, 5009, 5519, 5639, 5849, 6131, 6359, 6689, 6701
OFFSET
1,1
COMMENTS
Subsequence of A175914.
MATHEMATICA
lst={}; Do[p1=Prime[n]; p2=p1+2; If[PrimeQ[p2]&&PrimeQ[p1+2*p2], AppendTo[lst, p1]], {n, 7!}]; lst
Reap[Do[p = Prime[m]; If[PrimeQ[p + 2 ] && PrimeQ[3 p + 4], Sow[p]], {m, 10^3}]][[2, 1]](* Zak Seidov, Oct 14 2012 *)
Transpose[Select[Partition[Prime[Range[1000]], 2, 1], #[[2]]-#[[1]]==2 && PrimeQ[ #[[1]]+2#[[2]]]&]][[1]] (* Harvey P. Dale, Jan 28 2015 *)
PROG
(PARI) forprime(p=2, 7000, q=p+2; if(isprime(q)&& isprime(p+2*q), print1(p, ", ")))
(Magma) [p: p in PrimesUpTo(7000) | IsPrime(p+2) and IsPrime(3*p+4)]; // Vincenzo Librandi, Jan 29 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Definition and comment corrected by Zak Seidov, Dec 06 2010
STATUS
approved