SQL>
SQL> create sequence seq1 start with 10 increment by 1;

Sequence created.

SQL> select seq1.nextval from dual;

   NEXTVAL
----------
        10

1 row selected.

SQL>
SQL> create sequence seq2 start with 17 increment by 1;

Sequence created.

SQL> select seq2.nextval from dual;

   NEXTVAL
----------
        17

1 row selected.

SQL>
SQL> create sequence seq3 start with 56 increment by 1;

Sequence created.

SQL> select seq3.nextval from dual;

   NEXTVAL
----------
        56

1 row selected.

SQL>
SQL> create sequence seq4 start with 99 increment by 1;

Sequence created.

SQL> select seq4.nextval from dual;

   NEXTVAL
----------
        99

1 row selected.

SQL>
SQL>
SQL> declare
  2    nv int;
  3  begin
  4  for i in ( select sequence_name from user_sequences
  5  )
  6  loop
  7    execute immediate 'select '||i.sequence_name||'.nextval from dual' into nv;
  8    execute immediate 'alter sequence '||i.sequence_name||' increment by -'||nv||' minvalue 0';
  9    execute immediate 'select '||i.sequence_name||'.nextval from dual' into nv;
 10    execute immediate 'alter sequence '||i.sequence_name||' increment by 1';
 11  end loop;
 12  end;
 13  /

PL/SQL procedure successfully completed.

SQL>
SQL> select seq1.nextval from dual;

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

1 row selected.

SQL> select seq2.nextval from dual;

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

1 row selected.

SQL> select seq3.nextval from dual;

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

1 row selected.

SQL> select seq4.nextval from dual;

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

1 row selected.

SQL>