I agree w/ Varaali in that although Pandu can be considered Vyasa's son, Kunti can't be considered his DIL for the reasons she described. Like the Upanayan and all that, even a marriage would have made Kunti the kulvadhu of Vichitravirya/Ambalika, not Vyasa.
Anyway, my answer to your question here is Ajmidha
You went from Janamejaya - Parikshit - 1 generation
Parikshit - Arjun - 2 generations
Arjun - Shantanu - 3 generations
So the answer would be 4 generations above Shantanu. Shantanu's father was Jahnu, whose father was Kuru, whose father was Ruksha, whose father was Ajmidha.
Am I correct in either line of reasoning, or actual answer? If I'm right in the former but wrong in the latter, then who do you have 4 generations above Shantanu?
Hasti was the father of Ajmidha, and 4 generations after Bharata. I don't think this question would include Bharat, since it went just by Janamejaya's ancestrial lineage, which is why Shivang put Arjun instead of Yudhisthir in the chain. But it may have been Shivang's answer, assuming that he may not have expected anyone to know about Ajmidha.
Edited by .Vrish. - 13 January 2012 at 3:48am