SQL> create sequence test_seq
  2  start with 1 
  3  increment by 1;

Sequence created.

SQL> ed
Wrote file afiedt.buf

  1* select test_seq.nextval from dual
SQL> /.

   NEXTVAL
----------
         1

SQL> /

   NEXTVAL
----------
         2

SQL> select test_seq.currval from dual;

   CURRVAL
----------
         2

SQL> ed
Wrote file afiedt.buf

  1  declare
  2  dumm number;
  3  begin
  4  for mag in 1..240 loop
  5    select test_seq.nextval into dumm from dual ;
  6  end loop;
  7* end;
SQL> /

PL/SQL procedure successfully completed.

SQL> select  test_seq.currval from dual;

   CURRVAL
----------
       242