Dragon Ball. People start at 100 No and work up to 100billion.

And sure. If that's the way we do it. Still, I feel time is needed for saiyn to get into the human society, and begin reproducing often. 

But 1 single Half Saiyan spot will be fullfillable. And I personally dunno how to peg halfies with tails. Trunks and Goten had no tails, and that's 2 > 1 Gohan. Any ideas on the tails thing?