CREATE TABLE table_18729 ("#" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( millions ) " TEXT)

Who wrote the episode with production code 1ANJ01?
SELECT "Written by" FROM table_18729 WHERE "Production code" = '1ANJ01'
SELECT "Written by" FROM "table_18729" WHERE "Production code" = '1ANJ01'