Thread: From Elros to Aragorn
There is probably an answer somewhere in HoME, but just using the notes in the Appendices of RotK and UT it is difficult to answer. Including Elros, there were 24 Numenorian kings (or queens). Including Elendil, there were 25 kings in Arnor/Artherdain and then 16 Chieftains (Aragorn II being the 16th). Unfortunately, the answer is not as easy as adding these together (which would be 65 including both Elros and Aragorn). Elendil was not descended from the last Numenorian king, but from Tar-Elendil, the 4th Numenorian king, via his eldest daughter, Silmarien. I am unsure how many generations there were between Silmarien, her son Valandil, and Elendil's father, Amandil.
Supposing the line of Silmarien had similar longevity to the line of Numenorian kings, I would guess the number to be similar - eg. 65 generations from Elros to Aragorn II, but an early death in either line could cause the number to differ.