Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_11630008_7 ( series__number VARCHAR, production_code VARCHAR )

### Question ###
What is the number of series with production code 503?

### Accurate SQL ###

SELECT COUNT(series__number) FROM table_11630008_7 WHERE production_code = 503