SEQUENCES 
Using the
system table
SEQUENCES, you can determine the following database information:
sequences with an incremental value that is not +1 and the value limits of the sequences
SELECT owner, sequence_name, increment_by, min_value, max_value
FROM DOMAIN.SEQUENCES
WHERE increment_by <> 1
All sequences with a positive, incremental value. The values are not assigned cyclically, and there are only 1000 free values.
SELECT owner, sequence_name, last_number, max_value
FROM DOMAIN.SEQUENCES
WHERE increment_by > 0
AND cycle_flag = 'N'
AND max_value - last_number <= 1000
Current value of your own sequence MYSEQ
SELECT last_number
FROM DOMAIN.SEQUENCES
WHERE owner = user
AND sequence_name = 'MYSEQ'
Last value assigned by the current database session to the own sequence MYSEQ
SELECT user.myseq.currval
FROM DUAL