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
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
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