Rule finder in Excel

Originally Posted by sandy666

B1: =IF(A1=5,TRUE,"") and drag down
or
select whole range, go to Conditional Formatting.

Attachment 553193

Sorry, probably you misunderstood question.

I'm not trying to find position of number 5, I'm trying to predict when number 5 will show up.

For example, if we imagine the empty list and we start to add numbers 4,2,3,4,3 etc. I want to predict when
the number 5 will be added while using attached excel sheet (Book123) as sample.
This list is a sample and I'm trying to explain when number 5 will show up.
This is collected data in the past and I didn't know the exact sequence before.