The formula will not work if the data is arranged in a row.
It has to be in a column, starting at row 1 (one).
To make it work at any other starting row, you have to
bring seq into a displayed column and refer to seq instead of row().
Seq is a simple counting sequence 1,2,3....n as shown:
1 12 36
2
3
4
5 11 77
6
7
8
9
10
11
12
13 11 77
14
15
16
17
18
19
20
21 12 36
22
23
24
25 999 #N/A

The last number (999) will give a #N/A since it only serves
to define how many spaces are below the number 12.
If your data is arranged in a horizontal row, you can make
it work by substituting row refs with column refs.
Using R1C1 ref style might help.