Howdie all.
I've used some C# code to create my own fibbnoacci series macro.
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Sub fibbonacci()
Dim i As Long
Dim j As Long
Dim N As Long
Dim fib As Long

i = -1
j = 1

While (fib <= 6000000000#)
fib = i + j
i = j
j = fib

Wend
MsgBox "The Fibbonacci # for this series is: " & fib

End Sub
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It works good, with no problems. Well, at least until I reach 1.84 billion.

What I want to do is to add a "time" function with a 9 month limiter. I.e.,
each iteration has an output with each 9 months of time, and a 13 to 17 year
start point for each subsequent iteration set.
E.g.,
the fibbonacci numbers are
1, 1, 2, 3, 5, 8, 13, 21,.......
So, my first set where 1 and 1 become 2, is at time = 9 months.
my next set where 2 becomes 3 is at least 9 months, and each subsequent 9
months ++
I then want to do an offshoot from that, essentially starting over with each
13 to 17 years.

My overall goal is a population growth analysis for personal purposes. Back
when I was taking my math classes, one of my professors told me that the
fibbonacci series was developed to analyze rabbit population growth.

I realize that this might be over the top of what is done here, but I wanted
to at least ask. So, if it is, please let me know.
Thank you for your helps.
Best,
SteveB.