document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=13443>Question 13443</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find a counterexample to the following statement:<BR>\n" );
document.write( "If p is a prime number, then 2p-1 is prime.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #6797 by </B><A HREF=/tutors/aboutme.mpl?userid=rapaljer><B>rapaljer(4671)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rapaljer><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=rapaljer><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=6797\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How about 5, 13, or 23?  There are a TON of examples of primes p such 2p-1 is NOT a prime.\r<BR>\n" );
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document.write( "5*2-1 = 9 which is NOT a prime.<BR>\n" );
document.write( "2*13 - 1 = 25 which is NOT a prime.<BR>\n" );
document.write( "2*23 - 1 = 45 which is NOT a prime.\r<BR>\n" );
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document.write( "R^2 at SCC </SPAN>\n" );
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