<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=us-ascii" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 8.00.7600.16671"></HEAD> <BODY> <DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN class=991331211-05112010>Luke, you'd better ignore my third approach and follow the instructions of Todd.</SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN class=991331211-05112010>My method is far more difficult to implement than Todd's methods.</SPAN></FONT></DIV> <DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN class=991331211-05112010>Jos</SPAN></FONT></DIV><BR> <BLOCKQUOTE style="BORDER-LEFT: #0000ff 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px" dir=ltr> <DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left> <HR tabIndex=-1> <FONT size=2 face=Tahoma><B>From:</B> users-bounces@racket-lang.org [mailto:users-bounces@racket-lang.org] <B>On Behalf Of </B>Jos Koot<BR><B>Sent:</B> 05 November 2010 12:06<BR><B>To:</B> 'Todd O'Bryan'; lukejordan@gmail.com<BR><B>Cc:</B> users@racket-lang.org<BR><B>Subject:</B> Re: [racket] Generative recursion<BR></FONT><BR></DIV> <DIV></DIV> <DIV dir=ltr align=left><SPAN class=374210011-05112010><FONT color=#0000ff size=2 face=Arial>Actually there is one more way. We only have to check numbers 1 up to the integer-sqrt of n. For each check whose remainder is 0, we immediately have two divisors, the checking number and the quotient (except when these two are equal, giving one divisor only -this happens only when n is a square-))</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=374210011-05112010><FONT color=#0000ff size=2 face=Arial></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=374210011-05112010><FONT color=#0000ff size=2 face=Arial>Jos</FONT></SPAN></DIV> <DIV dir=ltr align=left> <HR tabIndex=-1> </DIV></BLOCKQUOTE></BODY></HTML>