Help with Exponential Forumla

[olismith89]

Hi there,

I am trying to create an exponential formula but I can't wrap my head around it.

Essentially, I want to be able to enter X (see below) into cell A1 and have the result appear in A2.

Nerdy background for my problem - it's for a D&D game where characters will spend X amount of time within a separate dimension. With each hour they spend, the time in their home dimension advances exponentially.
1 hour inside = 1 hour outside
+1
2 hours inside = 2 hours outside
+2
3 hours inside = 4 hours outside
+3
4 hours inside = 7 hours outside
+4
5 hours inside = 11 hours outside
Etc.

Each hour, the time on the outside increases exponentially starting at +1, then +2, +3, +4 etc. So if they spent 8 hours inside, it would be 1+2+4+7+11+16+22+29 = 92 hours.

I want to be able to enter X as the amount of time they spent inside this dimension and have the formula work out the exponential and total it to show how much time has passed in their home dimension.

I'm ok at maths but not very good with exponentials so I can't even work out a real-world formula for my problem. Any maths wizards who know a thing or two about excel, please help!

Hopefully the example makes sense.

 

[Marcelo Branco]

Maybe something like this...

Pasta2
	A	B
1	Hours Inside	Result
2	8	92
3	3	7
4	4	14
5	2	2
6	5	25
7	1	1
8	7	63
Plan1

Cell Formulas
Range	Formula
B2:B8	B2	=IF(A2=2,2,SUMPRODUCT((ROW(A$1:INDEX(A:A,A2))-1)*ROW(A$1:INDEX(A:A,A2))/2+1))

M.