user: Question: For series number 256, what was the original air date?
Columns: ['Series #', 'Season #', 'Title', 'Directed by', 'Written by', 'Original air date']
Types: ['real', 'real', 'text', 'text', 'text', 'text']
Sample row: [246.0, 1.0, '"Cañon City"', 'Christopher Chulack', 'Lisa Zwerling , John Wells and Joe Sachs', 'September22,2005']
SQL:

assistant: SELECT "Original air date" FROM "Table" WHERE "Series #" = 256.0;