SQL> archive log list;
Database log mode              No Archive Mode
Automatic archival             Disabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     13
Current log sequence           15
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area  409194496 bytes
Fixed Size                  2228864 bytes
Variable Size             310381952 bytes
Database Buffers           92274688 bytes
Redo Buffers                4308992 bytes
Database mounted.
SQL> alter database archivelog;

Database altered.

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     13
Next log sequence to archive   15
Current log sequence           15
SQL> shutdown immediate;
ORA-01109: database not open

Database dismounted.
ORACLE instance shut down.
SQL> alter database open;
ORACLE instance started.

Total System Global Area  409194496 bytes
Fixed Size                  2228864 bytes
Variable Size             310381952 bytes
Database Buffers           92274688 bytes
Redo Buffers                4308992 bytes
Database mounted.
Database opened.
SQL> alter system archive log start;

System altered.

SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence     13
Next log sequence to archive   15
Current log sequence           15
SQL>