PL/SQL - how to identify sequences used by tables?
You can query with this one:
SELECT 
    TABLE_OWNER, TABLE_NAME, 
    REFERENCED_OWNER AS SEQUENCE_OWNER, REFERENCED_NAME AS SEQUENCE_NAME
FROM ALL_DEPENDENCIES d
    JOIN ALL_TRIGGERS t ON TRIGGER_NAME = d.NAME AND t.OWNER = d.OWNER
WHERE REFERENCED_TYPE = 'SEQUENCE';

Note, a sequence might be used by more than one trigger. And a sequence can be used also by function, procedure, package, insert, update, etc, which is not covered by this query.
Also this query does not cover IDENTITY columns and sequences, they are hidden.
It depends what you mean by &quot;identify sequences used by tables&quot;?