10^N+1

Housemouse · 2008-05-23, 13:36

For all N>2, is 10^N+1 always composite?

wpolly · 2008-05-23, 13:39

http://www1.uni-hamburg.de/RRZ/W.Keller/GFN10.html

henryzz · 2008-05-23, 15:27

http://www.mersenneforum.org/showthread.php?t=8848

geoff · 2008-05-28, 00:20

10^2^23+1 = 10^8388608+1 is the smallest candidate that hasn't yet been shown to be composite. It would take about 89 days to do a PRP test on this number using a 2.66GHz Core 2. Some more trial factoring would probably be worthwhile before starting the PRP test.

2008-05-23, 13:36	#1
Housemouse Feb 2008 2⁵ Posts	10^N+1 For all N>2, is 10^N+1 always composite?

2008-05-23, 13:39	#2
wpolly Sep 2002 Vienna, Austria 3·73 Posts	http://www1.uni-hamburg.de/RRZ/W.Keller/GFN10.html

2008-05-23, 15:27	#3
henryzz Just call me Henry "David" Sep 2007 Liverpool (GMT/BST) 2·5·599 Posts	http://www.mersenneforum.org/showthread.php?t=8848

2008-05-28, 00:20	#4
geoff Mar 2003 New Zealand 13·89 Posts	10^2^23+1 = 10^8388608+1 is the smallest candidate that hasn't yet been shown to be composite. It would take about 89 days to do a PRP test on this number using a 2.66GHz Core 2. Some more trial factoring would probably be worthwhile before starting the PRP test.