user: Question: What was the attendance when lincoln city was the Opponents with H/a of a?
Columns: ['Date', 'Opponents', 'H / A', 'Result F – A', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['5 September 1903', 'Bristol City', 'H', '2 – 2', 40000.0]
SQL:

assistant: SELECT "Attendance" FROM "Table" WHERE "Opponents" = 'lincoln city' AND "H / A" = 'a';