Question: I need to ad the next sequence number in Column A automatically when I fill enter the next value in Column B. This sounds confused. Just see the snap so you will get the clear picture[![enter image description here](https://i.stack.imgur.com/91WEn.png)](https://i.stack.imgur.com/91WEn.png).

This should be done without usual dragging option. Is there any way

Answer: 
Make the Value of A1 equal to 1 and then from the A2 use the formula:

```
=IF(B3<>"",A2+1," ")

```

Drag this formula for the whole column.

In my solution I have a drag, but it is to define the formula for each of the fields. (I'm not sure if is this you are trying to avoid when you say 

> 
> without the usual dragging option
> 
> 
> 

)
You can also do this without using macro and formula:

1. Type first 2 value to the cell to establish the pattern
2. highlight the cell range
3. Under Home tag -> select Fill -> choose Series
4. Follow the image and Select OK

[![enter image description here](https://i.stack.imgur.com/lzvLJ.png)](https://i.stack.imgur.com/lzvLJ.png)