In which TV series is Laura Ingalls a main character?

In which TV series is Richie Cunningham a main character? Who played Charles Ingalls in 'Little House on the Prairie'? In which TV series is Charles Ingalls a main character? Who played Laura Ingalls in 'Little House on the Prairie'? Who played George Jefferson in 'The Jeffersons'? Who played Vinnie Barbarino in 'Welcome Back, Kotter'? In which TV series is Vinnie Barbarino a main character? Who played Jack Tripper in 'Three's Company'?