On-Line Encyclopedia of Integer Sequences For an off beat web site of interest to math nerds try out On-line Encycloperdia of Integer Sequences. Neil A.J. Sloane of AT&T Shannon Labs in Florham Park, N.J., has been collecting number sequences ever since he was a graduate student at Cornell University in the 1960s. Sloane has some number sequence puzzles at http://www.research.att.com/~njas/sequences/Spuzzle.html. When you give up, you can just click on a link to see the answer.