ERROR at line 6: ORA-06550: line 6, column 36: PLS-00103: Encountered the symbol "(" when expecting one of the following: )

DECLARE
2  N NUMBER(4):=&N;
3  BEGIN
4  FOR I IN 1..10
5  LOOP
6  DBMS_OUTPUT.PUT_LINE(N||'*'||I||'='(N));
7  END LOOP;
8* END;

SQL>*ERROR at line 6:
ORA-06550: line 6, column 36:
PLS-00103: Encountered the symbol "(" when expecting one of the following:
) , * & = - + < / > at in is mod remainder not rem =>
<an exponent=""> <> or != or ~= >= <= <> and or like like2
like4 likec as between from using || member submultiset
The symbol "," was substituted for "(" to continue.</an>