Lucas–Lehmer–Riesel test
In mathematics , the Lucas–Lehmer–Riesel test is a primality test for numbers of the form "N" = "k" ⋅ 2"n" − 1 , with "k" < 2"n" . 
<triplet> Lucas–Lehmer–Riesel test <subj> primality test <obj> instance of