What episode number of the series is "the coming of arthur (part 1)"?
CREATE TABLE "table1_29106680_1" (
  "no_overall" real,
  "no_for_series" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "uk_viewers_million" text
);
SELECT "no_for_series" FROM "table1_29106680_1" WHERE "title"='\"The Coming of Arthur (Part 1)\"';