The power of 5..........................10 #'s in the pf...................5 primes.............5 non primes................15 is the 2nd non prime.............in the sequence............of 3, 5, 7, 9, etc.............



3 (5's).........or is it like 35?  Or 15?  Or both.......?  Sometimes it is how u look at stuff...........

square root(13) =

3.60555127546