I have a column of numbers :

3

0

4

2

1

0

5

0

3

2

0

2

I am trying to get the number of times the sum of two consecutive rows is below 3. In this example 4 (i.e. 2+1,1+0,2+0 and 0+2).

I tried a way around with this formula :

=SUMPRODUCT(--(FREQUENCY(IF(C5:C16<2, ROW(C5:C16)), IF(C5:C16>=2, ROW(C5:C16)))>=2)) based on an old post but it is 1) not exactly what I am looking for and 2) not working anyway here for some reason I don't understand.

THANK YOU VERY MUCH FOR YOUR HELP !