Factorial question

[M.M]

An example of what Im trying to do:

Four cells in the same column A1:A4 with values 1,2,3,4 respectively.

Assuming that the value of A4 factorial, so A4!, would be A4*A3*A2*A1, then
the function I am trying to insert would be A4!*A3!*A2!*A1!.

I want it to be, however, so there is an input cell where I can insert the
number of cell's I want included, which in this case was 4.

While this is relatively simple if there are just 4 cells involved,
ultimately I will be using up to 100 cells. As yet I have not been able to
produce an appropriate function to do this, and am not even sure if Excel is
able to do this. Any help is appreciated.

 

[Ron Rosenfeld]

An example of what Im trying to do:

Four cells in the same column A1:A4 with values 1,2,3,4 respectively.

Assuming that the value of A4 factorial, so A4!, would be A4*A3*A2*A1, then
the function I am trying to insert would be A4!*A3!*A2!*A1!.

I want it to be, however, so there is an input cell where I can insert the
number of cell's I want included, which in this case was 4.

While this is relatively simple if there are just 4 cells involved,
ultimately I will be using up to 100 cells. As yet I have not been able to
produce an appropriate function to do this, and am not even sure if Excel is
able to do this. Any help is appreciated.

Will not the FACT worksheetfunction do what you require?
--ron

 

[M.M]

The FACT worksheet function is useful to find A4!, but I then want to add it
by the factorial of every cell before it i.e A3!+A2!+A1!. Sorry I made a
mistake in my original post, I want to add the factorials of each cell, not
multiply them. So ultimately I would want A4!+A3!+A2!+A1!. Mathematically I
want a Sigma Notation of FACT(AN), with N being the number of cells. Please
advise if sigma notations, or any alternative way I can solve this, are
possible in excel.

 

[Bernie Deitrick]

MM.

Array enter (enter using Ctrl-shift-Enter)

=SUM(FACT(ROW(A1:AXXX)))
like
=SUM(FACT(ROW(A1:A4)))

Replace XXX with N.....

HTH,
Bernie
MS Excel MVP

 

[M.M]

Thanks Bernie, helped alot

MM.

Array enter (enter using Ctrl-shift-Enter)

=SUM(FACT(ROW(A1:AXXX)))
like
=SUM(FACT(ROW(A1:A4)))

Replace XXX with N.....

HTH,
Bernie
MS Excel MVP

 

[Ron Rosenfeld]

The FACT worksheet function is useful to find A4!, but I then want to add it
by the factorial of every cell before it i.e A3!+A2!+A1!. Sorry I made a
mistake in my original post, I want to add the factorials of each cell, not
multiply them. So ultimately I would want A4!+A3!+A2!+A1!. Mathematically I
want a Sigma Notation of FACT(AN), with N being the number of cells. Please
advise if sigma notations, or any alternative way I can solve this, are
possible in excel.

Given n>=2:

This formula must be **array-entered**:

=SUM(FACT(ROW(INDIRECT("1:"&n))))
----------------------------------------

To **array-enter** a formula, after entering
the formula into the cell or formula bar, hold down
<ctrl><shift> while hitting <enter>. If you did this
correctly, Excel will place braces {...} around the formula.
--ron