Return a value if there are 3 or more consecutive rows

[Xy019]

Hi! I need help in finding 3 or more consecutive rows. I have until row 40000 (most are blank but data will be entered in the future)

On COL AF - values will only be 0 and 1, I need to return a value if there are 3 or more consecutive 1s on COL AF

Any input would be great!

Thank you!

 

[AlanY]

not the most elegant

Book1
	A	B
1	0
2	0
3	1	X
4	1	X
5	1	X
6	1	X
7	1	X
8	1	X
9	0
10	1
11	0
12	1	X
13	1	X
14	1	X
15	0
Sheet1

Cell Formulas
Range	Formula
B3:B15	B3	=IF(OR(SUM(A1:A3)=3,SUM(A2:A4)=3,SUM(A3:A5)=3),"X","")

Cells with Conditional Formatting
Cell	Condition		Cell Format	Stop If True
A3:A15	Expression	=OR(SUM(A1:A3)=3,SUM(A2:A4)=3,SUM(A3:A5)=3)	text	NO

Cell Formulas
Range	Formula
B3:B15	B3	=IF(OR(SUM(A1:A3)=3,SUM(A2:A4)=3,SUM(A3:A5)=3),"X","")

 

[Legacy 143009]

In AG3 paste this:

=IF(COUNTIF(AF1:AF3,1)>=3,TRUE,FALSE)