Hi. I believe you are looking for the number of Subsets, which as you
mentioned, does include an empty set.
2^n

http://mathworld.wolfram.com/Subset.html

--
HTH :)
Dana DeLouis
Windows XP & Office 2003


"Mark Siler" wrote in message
...
The proposed formula doesn't work. If you have 4 letters the formula
returns 12 when the answer should be 16. I've figured out that if you
list the number of letters as binary. 64 32 16 8 4
2 1 where counting from the right each place is the number of letters.
If there are 4 letters then it would be 8 4 2 1 and if you add
up all the number in this case you get 15 then add one for the options of
where places are empty. This is how I figured it was 16 for 4 letters. 5
letters would be 16+8+4+2+1+1=32. I'm still looking for a formula that
will do this???

"Jaleel" wrote in message
...
Hi,

Try this formula:

N+2+(N*(N-1)/2)

Where N stands for number of letters.

Regards,

Jaleel

"Mark Siler" wrote:

I'm trying to figure what function I need to use. I unerstand that when
order does matter I should use Permutations and Combinations when it
doesn't. For example if I want to know how many two letter group I can
make
from the word CAT and order does not matter I'd use Combinations and the
results would be CA, CT and AT. But here's my question, what if I needed
to
know how many different Combinations I could have from three blank spots
to
all letters. On something small I like CAT I can just write them out.

CAT
CA_
CT_
AT_
C_ _
A_ _
T_ _
_ _ _

COMBIN does't work. The first number I'd enter for the formula would be
the
total number of letters, in this case 3. The next number is the number
of
groups and this is what seems to be the issue. I got the right answer
when I
did =COMBIN(3,3)+COMBIN(3,2)+COMBIM(3,1)+COMBIN(3,0), but what do I do
if I
have 15 letters. The must be a function that does this that I'm not
finding??

Thanks,
Mark