login
A153590
Primes p such that p^2 + 3p + 1 is also prime.
5
2, 3, 5, 7, 19, 23, 29, 37, 43, 47, 53, 59, 67, 113, 137, 139, 157, 163, 173, 179, 229, 239, 257, 263, 293, 313, 349, 353, 359, 373, 379, 419, 449, 467, 499, 503, 509, 547, 577, 587, 593, 617, 643, 647, 653, 719, 727, 797, 883, 929, 967, 983, 997, 1013, 1033, 1049
OFFSET
1,1
COMMENTS
Primes p such that (p*(p+1)) + (p+(p+1)) is prime. Primes p such that sum of product and the sum of p and the nextNumber is prime. - Vladimir Joseph Stephan Orlovsky, Mar 13 2010
LINKS
EXAMPLE
For p = 2, p^2 + 3p + 1 = 11; p = 67, p^2 + 3p + 1 = 4691; for p = 419, p^2 + 3p + 1 = 176819.
MATHEMATICA
Select[Table[Prime[n], {n, 6!}], PrimeQ[#^2+3*#+1]&] (* Vladimir Joseph Stephan Orlovsky, Mar 13 2010 *)
PROG
(Magma) [ p: p in PrimesUpTo(1050) | IsPrime(p^2+3*p+1) ];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 29 2008
EXTENSIONS
Edited and extended by Klaus Brockhaus, Jan 01 2009
STATUS
approved