How many Huckleberry Hound episodes were aired on 1960.09.18?
CREATE TABLE "season_3_1960" (
  "n" real,
  "ep" real,
  "huckleberry_hound" text,
  "pixie_and_dixie" text,
  "hokey_wolf" text,
  "air_date" text,
  "credited_animators" text
);
SELECT COUNT("huckleberry_hound") FROM "season_3_1960" WHERE "air_date"='1960.09.18';