How to reference the result of a formula in an IF function

I am trying to put together a simple table in Excel. In column A I have a formula that returns a sequential number sequence; 1, 2, 3, 4 etc. In column B I want an IF function that returns a value if the corresponding number in column A is less than 50.

So far I have =IF(A1<50,”415”)

However, Excel seems to be referencing the formula in A1 rather than the result so it keeps returning a false result. How do I get it to reference the resulting value rather than the formula?

And to clarify, I need to use a formula in A as I need to be able to delete rows and have Excel renumber the column accordingly.

Thanks