CREATE TABLE table_21755 ("Gatchaman" TEXT, "Battle of the Planets" TEXT, "G-Force" TEXT, "Eagle Riders" TEXT, "OVA  ( Harmony Gold Dub ) " TEXT)

Which gatchaman has eagle riders as lukan?
SELECT "Gatchaman" FROM table_21755 WHERE "Eagle Riders" = 'Lukan'
SELECT "Gatchaman" FROM "table_21755" WHERE "Eagle Riders" = 'Lukan'