How many movies have Fujiko F. Fujio and Yoshimasa Iiyama collaborated on?

They have worked on 18 movies together! Their first movie together was Doraemon: The Record of Nobita, Spaceblazer (1981) while their highest rated movie together was Doraemon: Nobita's Three Visionary Swordsmen (1994). They have not worked together since Doraemon: Nobita and the Legend of the Sun King (2000). They are most known for their family films together.