Links

Videos

nth Term of an Arithmetic Sequence  (time: 1:09)
http://www.youtube.com/watch?v=eYcKyshFXQA

Geometric Sequences (time: 9:50)
http://www.youtube.com/watch?v=yz20bOBg2pw

Fibonacci Sequences (time: 1:52)
http://www.youtube.com/watch?v=fuCPXzAhNM4

History

This is one of the best all around sites that I have found. It is titled "The MacTutor History of Mathematics Archive."
http://www-history.mcs.st-and.ac.uk/~history/

This is an award-winning site that links to all sorts of mathematics information.
http://archives.math.utk.edu/

Fibonacci:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Fibonacci.html

Reference Topics

Here is the Mensa home page:
http://www.mensa.org/

Some practice with sequences and summation notation (which we introduce in the next section) can be found at this site:
http://www.richland.cc.il.us/james/lecture/m116/sequences/sequences.html

There is an interesting association between the Fibonacci numbers and the golden section. This relationship is explored at this site:
http://ualr.edu/lasmoller/fibonacci.html

Here is a site which derives Binet's formula (Problem 57):
http://mathforum.org/library/drmath/view/52677.html