CODE CONJETURE COLLATZ

ZLOSADA · Apr 4, 2023

Create a function called "CollatzMaxTotal" basically says: Pick any natural number n. If n is even, take n and divide by 2. If n is odd, multiply n by 3 and add 1. Repeat this algorithm and regardless of what number you picked to begin with, you will always end at 1 that given a number:
If the number is not a positive integer, generate a text that says: "The number is not a positive integer", but if it is a positive integer, generate a text that says the maximum value that the number reached with the Collatz conjecture and the number of steps it takes to get to number 1 for the first time. Example:
If the number is 7 then the function outputs: The maximum value was 52 and to get to 1 it takes 16 steps.
If the number is 9.2 then the function outputs: The number is not a positive integer
If the number is 35 then the function outputs: The maximum value was 160 and it takes 13 steps to get to 1.
Thank you

Mario_R · Apr 5, 2023

Hello. Interesting conjeture:

This is an array function that occupies two cells.
If you don't know how to incorporate it into your sheet, please comment.

PHP:

Function CollatzMaxTotal(n)
Dim i&, j&, M&, v As Boolean
Rem ----------------------->
CollatzMaxTotal = Array("Wrong", "number")
If Not IsNumeric(n) Then Exit Function
If n < 1 Or n <> Int(n) Then Exit Function
Rem ----------------------->
j = n: M = j
Do While j <> 1
  If (j Mod 2) = 0 Then j = j / 2 Else j = 3 * j + 1
  M = Application.Max(M, j): i = 1 + i
Loop
Rem ----------------------->
CollatzMaxTotal = Array(M, i)
End Function

Test_1.xlsm