I did not count mobile games, because I often wonder if they're by the third-party developers of the game than Sega themselves.
The ones come from Japan (Chain Chronicle, Sonic Runners, Dx2 Shin Megami Tensei, Idola Phantasy Star Saga) were from SEGA themselves.
The one from western, has to be divided into two categories :
1. Original SEGA franchises (Chuchu Rocket Universe, Sonic Dash, Sonic Forces, SEGA Heroes) usually made by second parties (SEGA Hardlight, Demiurge, Three Rings, etc).
2. Acquired SEGA franchises (Total War, Company of Heroes) usually made by third parties.
The new Shining Force mobile is kinda exception though.
The franchise is being lent out to third party.