Multi-row formula

[Mo1995]

I have a series of Invoices and I want to check if there're any gaps or missing serials

I have formulated the tool as follows but the output is incorrect :

([Row-1:Reference#] + 1) = [Row+1:Reference#] OR [RecordID] = 1

this is the input :

this is the output :

I want the output to show the gap difference whenever it happens

i.e between rows 3 and 4 there're 9 serials missing , that's what I want as an output in the 3rd colum

what am I doing wrong here ??

[Qiu · Accepted solution]

@Mo1995 
Maybe you almost there. 😁

[Mo1995]

worked like magic