633
Comment:

640

Deletions are marked like this.  Additions are marked like this. 
Line 3:  Line 3: 
* $2^n \pm 1$ for $n ≤ 100$ [http://www.euronet.nl/users/bota/mediump.htm]  * $2^n \pm 1$ for $1200 < n < 10000$ [http://www.euronet.nl/users/bota/mediump.htm] 
a^n \pm 1 for a = 2, 3, 5, 6, 7, 10, 11, 12 and large exponents n [http://homes.cerias.purdue.edu/~ssw/cun/index.html]
a^n \pm 1 for a ≤ 13 and a not a perfect number [http://wwwmaths.anu.edu.au/~brent/factors.html]
2^n \pm 1 for 1200 < n < 10000 [http://www.euronet.nl/users/bota/mediump.htm]
10^n \pm 1 for n ≤ 100 [http://www.swox.com/gmp/repunit.html]
p^p \pm 1 where p is a prime number and p < 180. [http://homes.cerias.purdue.edu/~ssw/bell/r1]
2^{2^n} + 1 (Fermat numbers) [http://www.prothsearch.net/fermat.html]
2^{3^n} \pm 1 [http://www.alpertron.com.ar/MODFERM.HTM]