OFFSET
1,1
COMMENTS
Generalized Fermat numbers of the form b^(2^n) + k with k = 3 here.
MATHEMATICA
Select[Prime@Range[3, 10^6]-3, PrimeQ[#^2 + 3] && PrimeQ[#^4 + 3] && PrimeQ[#^8 + 3] && PrimeQ[#^16 + 3] &] (* Giovanni Resta, May 05 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Robin Garcia, May 05 2013
EXTENSIONS
Missing terms a(2) and a(5) and a(12)-a(25) from Giovanni Resta, May 05 2013
STATUS
approved