OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
For p=5, (4*p^2-8*p-9)/3 = 17; for p=149, (4*p^2-8*p-9)/3 = 29201.
MAPLE
a := proc (n) if isprime(n) = true and type((4/3)*n^2-(8/3)*n-3, integer) = true and isprime((4/3)*n^2-(8/3)*n-3) = true then n else end if end proc: seq(a(n), n = 2 .. 4000); # Emeric Deutsch, Jan 20 2009
MATHEMATICA
Select[Prime[Range[2, 500]], PrimeQ[(4 #^2 - 8 # - 9)/3] &] (* Harvey P. Dale, May 20 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 18 2009
EXTENSIONS
Extended by Emeric Deutsch, Jan 20 2009
Formatting of definition clarified by Harvey P. Dale, May 20 2012
STATUS
approved