Question 149159
f(x)=x^2-x+41

if x=1 then f(1)=41 (prime)
if x=2 then f(2)=43 (prime)
if x=3 then f(3)=47 (prime)
if x=4 then f(4)=53 (prime)

but if x=41 f(41)=41^2 (composite)