Return list of row numbers of cells that contain a numeric value

I’d like to have a formula that will extract the row number of each numeric value. Also, I do not want to end up with empty cells (or values like "not numeric"). This needs to be a formula, for repeatability. For example, source column looks like this:

+--------+
| Foobar |
+--------+
| Foobar |
+--------+
| 123    |
+--------+
| 123    |
+--------+
| Foobar |
+--------+
| 123    |
+--------+

I want to end up with:

+---+
| 3 |
+---+
| 4 |
+---+
| 6 |
+---+

>Solution :

=FILTER(ROW(A1:A6),ISNUMBER(A1:A6)) if it starts in the first row

Else =TOCOL(SEQUENCE(ROWS(C2:C9))/C2:C9^0,2)