

The Prime Glossary: wheel factorization 
  To see if a number is prime via trial division (or to find its prime factors), we divide by all of the primes less than (or equal to) its square root. 
  Rather than divide by just the primes, it is sometimes more practical to divide by 2, 3, and 5; then divide by all the numbers congruent to 1, 7, 11, 13, 17, 19, 23, and 29 modulo 30again stopping when you reach the square root. 
  This type of factorization is called wheel factorization and the spokes are the list of integers prime to all of the primes we are using. 
 primes.utm.edu /glossary/page.php?sort=WheelFactorization (488 words) 
