CREATE TABLE "table1_13426649_1" (
  "num" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_millions" text
);

Question: When did the episode titled "Winterland" air for the first time? 
SQL: SELECT "original_air_date" FROM "table1_13426649_1" WHERE "title"='\"Winterland\"';

Question: How many different original air dates did the episode number 6 have? 
SQL: SELECT COUNT("original_air_date") FROM "table1_13426649_1" WHERE "num"=6;

Question: Who wrote the episode with production code 1ANJ01?
SQL: SELECT "written_by" FROM "table1_13426649_1" WHERE "production_code"='1ANJ01';