For many years,I've been looking for a calculator that could not only do large numbers,but
also write them to a file! I found Pari!

http://pari.math.u-bordeaux.fr/

It really works. Because the documentation that comes with it is in the stupd PDF format,
I wrote this little intro.

I downloaded the Win32 installation. Here is the deal.
After you install it,you can run gp.exe .It's a calculator that does huge numbers.
You can use all the regular operators.

+ addition
- subtraction
* multiplication
/ division
\ int division
^ power
% modulus

So,try typing "2^64". That will give you the correct answer!
Now,the best part is that you can write it to a file!
Try "write1(file,2^64)" . That will write the answer to a file called "file" .

GP is also a scripting language. I haven't figured it all out yet,but it has loads of commands.
Access the help by entering "?".

There are ways to read commands from a file. Could be useful for your own weird sequences.

This is an example of what it can do! Enter this!

a=1;for(b=1,256,a+=a;print(a))

That will print the first 256 powers of 2!
I figured that out by looking in the users manual and because I already know C.