Who are the seven demigods other than Piper Jason and Leo in next Great Prophecy?

You're likely thinking of the Seven of the Prophecy from Rick Riordan's *Heroes of Olympus* series.

Here are the seven demigods from the *Heroes of Olympus* series:

1. Percy Jackson (Son of Poseidon)

2. Annabeth Chase (Daughter of Athena)

3. Jason Grace (Son of Jupiter)

4. Piper McLean (Daughter of Aphrodite)

5. Leo Valdez (Son of Hephaestus)

6. Frank Zhang (Son of Mars)

7. Hazel Levesque (Daughter of Pluto)

While you correctly mentioned Jason, Piper, and Leo, the remaining four are Percy, Annabeth, Frank, and Hazel.