OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
select(n -> isprime(n*(n-1)-1) and isprime(n*(n+1)+1), [$1..1000]); # Robert Israel, Jan 04 2018
MATHEMATICA
Select[Range[6! ], PrimeQ[ #^2-(#+1)]&&PrimeQ[ #^2+(#+1)]&] (* Vladimir Joseph Stephan Orlovsky, Dec 19 2009 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Pierre CAMI, Dec 10 2004
EXTENSIONS
a(54)=755 inserted by Robert Israel, Jan 04 2018
STATUS
approved