missing number find out in conservative number series

With a formula this would be tricky and would need at least one helper column. With VBA it's trivial:

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WBD

You have some non number cells, ie 38A. What is supposed to happen to them? In the following code, it will do what you want so long as all non-numbers, ie. 38A have been removed from the list

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Please try at B2

Formula:

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Try:

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**Array formulas are not entered in the same way as 'standard' formulas. Instead of pressing just ENTER, you first hold down CTRL and SHIFT, and only then press ENTER. If you've done it correctly, you'll notice Excel puts curly brackets {} around the formula (though do not attempt to manually insert these yourself).
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I forgot to lock Cell.

J2
=IFERROR(AGGREGATE(15,6,ROW($A$1:INDEX(H:H,MAX($H$2:$H$37)-MIN($H$2:$H$37)))+MIN($H$2:$H$37)/ISNA(MATCH(ROW($A$1:INDEX(H:H,MAX($H$2:$H$37)-MIN($H$2:$H$37)))+MIN($H$2:$H$37),$H$2:$H$37,)),ROWS(J$2:J2)),"")