You have the wrong type of quotes around `seq $linecount`. You have single quotes, which make the whole phrase get treated as a single string. If you want to execute it and use the results you want backticks:

 `seq $linecount`

or, better now, use the `$(...)` syntax which does the same

 for num in $(seq $linecount)

or you could do it without the other program at all:

 num=1
 while [ "$num" -le "$linecount" ]; do
 ...
 ((num=num+1))
 done

If you're trying to print out the first `N` lines of the file though you should probably use just `head`:

 head -n "$linecount" misspelled