Burke's Sieve of Eratosthenes

<cfset timestart=now()>
<cfset xAry = arraynew(1)>
<cfloop from='1' to="35000" index='i'>
<cfset xAry[i] = true>
</cfloop>

<cfset i = 2>
<cfloop  condition='i le arraylen(xAry) / 2'>
<cfif xAry[i] is true>
          <cfset x = i>
          <cfloop  condition='i*x le arraylen(xAry)' >
              <cfset xAry[x*i] = false>
              <cfset x++>
          </cfloop>
        </cfif>
  <cfset i++>
</cfloop>
<cfset timeend=now()>

<cfoutput>started: #timeformat(timestart, 'hh:mm.ss tt')# - ended: #timeformat(timeend, 'hh:mm.ss tt')#<br /></cfoutput>

<cfoutput>
  <cfloop from='1' to='#arraylen(xAry)#' index='i'>
<cfif xAry[i] is true> #numberformat(i,'999,999,999,999,999')#&nbsp;&nbsp;</cfif>
  </cfloop>
</cfoutput>