user: Question: Which Week has a Result of l 20–13, and an Attendance larger than 49598?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'real']
Sample row: [1.0, 'September 21, 1975', 'at Philadelphia Eagles', 'W 23–14', 60798.0]
SQL:

assistant: SELECT "Week" FROM "Table" WHERE "Result" = 'l 20–13' AND "Attendance" > 49598.0;