CREATE TEMP SEQUENCE myseq2;
CREATE TEMPORARY SEQUENCE myseq3;
CREATE TEMP TABLE t1 (f1 SERIAL, 
                      f2 INT DEFAULT NEXTVAL('myseq2'),
                      f3 INT DEFAULT NEXTVAL('myseq3'::text)
);

DROP SEQUENCE t1_f1_seq;
DROP SEQUENCE myseq2;
DROP SEQUENCE myseq3;
DROP TABLE t1;
DROP SEQUENCE t1_f1_seq;
DROP SEQUENCE myseq2;