Number Theory Links

(1) Fermat factoring status

http://www.prothsearch.net/fermat.html

(2) Number Theory List

http://listserv.nodak.edu/archives/nmbrthry.html

Was found a 73-digit prime factor,

1808422353177349564546512035512530001279481259854248860454348989451026887

of (2^1181) - 1

(3) Pi Computation Record

http://bellard.org/pi/pi2700e9/announce.html

(4) Fun with numbers

http://www.mathpuzzle.com/numbers.html

See, for example: Numbers from 1 to 10 in Over 4000 Languages.

(5) The On-Line Encyclopedia of Integer Sequences

http://www.research.att.com/~njas/sequences/