



 
JP, Try some examples. Evaluate "the cube of the number plus five times the number plus 1" for numbers starting at 1, 2, 3 and so on. Each time check to see if "the cube of the number plus five times the number plus 1" is a prime. Yo don't need to go very far until you fine one that is not a prime. Penny  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 