.sequence_name != ?

When a sequence is created in 7.3.2, it appears you get a new table for each
sequence object.  Is it ever possible for the sequence_name in a sequence
relation not to match the name of the relation itself?

For example, suppose I create a table:
CREATE TABLE t1(id serial);

A new relation called 't1_id_seq' is created where
t1_id_seq.sequence_name = 't1_id_seq'

Is that always true?

Ed