login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A157978
Primes p such that 4*p - 3 is also a prime.
4
2, 5, 11, 19, 23, 29, 59, 61, 71, 79, 89, 101, 103, 109, 113, 131, 149, 151, 191, 193, 233, 239, 263, 283, 313, 331, 353, 359, 373, 389, 401, 431, 439, 479, 499, 521, 523, 541, 569, 571, 599, 619, 631, 653, 659, 673, 683, 701, 709, 739, 743, 751, 761, 773, 829
OFFSET
1,1
LINKS
MATHEMATICA
q=3; lst={}; Do[p=Prime[n]; If[PrimeQ[(q+1)*p-q], AppendTo[lst, p]], {n, 6!}]; lst
Select[Prime[Range[1000]], PrimeQ[4 # - 3]&] (* Vincenzo Librandi, Feb 03 2014 *)
PROG
(Magma) [n: n in [0..2000] | IsPrime(n) and IsPrime(4*n - 3)]; // Vincenzo Librandi, Feb 03 2014
KEYWORD
nonn,easy
AUTHOR
STATUS
approved