user: Question: Which Week has a Result of L 13-16 and an Opponent of at Buffalo Bills?
Columns: ['Week', 'Date', 'TV Time', 'Opponent', 'Result']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'September 3, 2000', 'ESPN 7:30 pm CDT', 'at Buffalo Bills', 'L 13-16']
SQL:

assistant: SELECT "Week" FROM "Table" WHERE "Result" = 'L 13-16' AND "Opponent" = 'at Buffalo Bills';