In geneology studies, there is a report often created called an ahnentafel report
a genealogical numbering system for listing a person's direct ancestors in a fixed sequence of ascent. The subject (proband or progenitor) of the ahnentafel is listed as No. 1, the subject's father as No. 2 and the mother as No. 3, the paternal grandparents as No. 4 and No. 5 and the maternal grandparents as No. 6 and No. 7, and so on, back through the generations.
While the term is originally German, it is routinely used in English language genealogy activities.
This term describes the report rather than the relationship, but it may suit, depending on the context of your usage.