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HP 25 Fibonacci sequence in one program step
10-14-2021, 07:04 PM (This post was last modified: 10-17-2021 03:41 PM by rprosperi.)
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RE: HP 25 Fibonacci sequence in one program step
(10-14-2021 02:13 PM)Albert Chan Wrote:  
(10-14-2021 10:03 AM)C.Ret Wrote:  [Image: f90aae99d109a6d152d80d03d0353a5e849c560e]

We can use this to get fib(n+m) = fib(m)*fib(n+1) + fib(m-1)*fib(n)

If n=m, we have fib(2n) = fib(n) * (fib(n+1) + fib(n-1))
Using this, we can can 1/sqrt(5) another way

φ^n ≈ fib(2n) / fib(n) = fib(n+1) + fib(n-1) ≈ fib(n) * (φ+1/φ) = fib(n) * √5

fib(n) = round(φ^n / √5)

Looks like more than 1 program step to me....

Also, where are those functions on an HP-25? I've looked at mine again today, and just can't see them anywhere...

--Bob Prosperi
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RE: HP 25 Fibonacci sequence in one program step - rprosperi - 10-14-2021 07:04 PM



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