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A124098
Primes p such that 3p -+ 4 are primes.
4
3, 5, 11, 19, 31, 59, 79, 89, 131, 151, 191, 199, 229, 241, 311, 389, 409, 431, 509, 521, 541, 661, 719, 739, 821, 971, 1109, 1151, 1181, 1451, 1549, 1669, 1759, 1801, 1949, 1951, 2011, 2039, 2069, 2089, 2111, 2131, 2341, 2411, 2671, 2699, 2791, 3001, 3181
OFFSET
1,1
FORMULA
a(n)= A125216(n)/3.
MATHEMATICA
lst={}; Do[p=Prime[n]; If[PrimeQ[3*p-4]&&PrimeQ[3*p+4], AppendTo[lst, p]], {n, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 16 2009 *)
Select[Prime[Range[500]], AllTrue[3#+{4, -4}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 02 2015 *)
PROG
(Magma) [p: p in PrimesUpTo(70000)| IsPrime(3*p-4)and IsPrime(3*p+4)] // Vincenzo Librandi, Jan 29 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Nov 26 2006
STATUS
approved