Finding all prime numbers before limit . These numbers are used to find prime factors .
sieveSundaram ( ) ; echo " Printing ▁ first ▁ few ▁ Smith ▁ Numbers " . " ▁ using ▁ isSmith ( ) STRNEWLINE " ; for ( $ i = 1 ; $ i < 500 ; $ i ++ ) if ( isSmith ( $ i ) ) echo $ i . " " ; ? >