no, that's not currently possible with scribus.
i understand in which context you might use it, and --
in a very different context -- i also could have used it.
but i wonder if and how scribus could provide that, without making its interface even more complex.
depending on the way you have defined your document, i can create a script for you that automates the typing of the numbers, but you will have to put a second frame on the left of your "real" text frame... and make sure that you have a fixed line height.
the result is similar to what you see in the document linked above:
- you don't need the zebra background of course
- and i can let you specify how often the number appears.
just ask for it, if you want the script... it's not that hard to create...