OFFSET
1,1
COMMENTS
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..10000
EXAMPLE
3*3-3-1=5 3*3-3+1=7, 5 and 7 twin primes so a(1)=3;
5*5-5-1=19 5*5-5+1=21 composite;
7*7-7-1=41 7*7-7+1=43, 41 and 43 twin primes so a(2)=7.
MATHEMATICA
Select[Prime[Range[2500]], PrimeQ[ #^2 - # - 1] && PrimeQ[ #^2 - # + 1] &] (* Stefan Steinerberger, Jul 22 2006 *)
Select[Prime[Range[2500]], AllTrue[#^2-#+{1, -1}, PrimeQ]&] (* Harvey P. Dale, Jul 25 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Jun 26 2006
EXTENSIONS
More terms from Stefan Steinerberger and Rick L. Shepherd, Jul 22 2006
STATUS
approved