OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..2000
EXAMPLE
42*31-1=1301, 42*31+1=1303; 48*31-1=1487, 48*31+1=1489; ...
MATHEMATICA
a=42; b=48; Select[Prime[Range[14^4]], PrimeQ[a*#-1]&&PrimeQ[a*#+1]&&PrimeQ[b*#-1]&&PrimeQ[b*#+1]&]
PROG
(Magma) [p: p in PrimesUpTo(1000)| IsPrime(42*p-1) and IsPrime(42*p+1) and IsPrime(48*p-1) and IsPrime(48*p+1)]; // Vincenzo Librandi, Nov 24 2010
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vladimir Joseph Stephan Orlovsky, May 15 2008
EXTENSIONS
More terms from Vincenzo Librandi, Apr 01 2010
STATUS
approved