SQL> create or replace type num_tab is table of number;
   2   /

Type created

SQL> 
SQL> create or replace function fibonacci_numb(p_num   number,
   2                                             p_prev2 number :=  0 ,
   3                                             p_prev1 number :=  1 )
   4     return num_tab is
   5     arr  num_tab := num_tab();
   6   begin
   7     if p_num- 2  >  0  then
   8       arr := fibonacci_numb(p_num -  1 , p_prev1, p_prev1 + p_prev2);
   9       arr.extend;
  10       arr(arr.last) := p_prev1;
  11     end if;
  12     if p_prev2 =  0  and p_num >=  2  then
  13       arr.extend;
  14       arr(arr.last) :=  0 ;
  15     end if;
  16     return arr;
  17   end;
  18   /

Function created

SQL> var p number;
SQL> exec :p:= 15 ;

PL/SQL procedure successfully completed
p
---------
 15 

SQL> 
SQL> select * from table(fibonacci_numb(:p+ 1 ))
   2   order by  1 
   3   /

COLUMN_VALUE
------------
            0 
            1 
            1 
            2 
            3 
            5 
            8 
           13 
           21 
           34 
           55 
           89 
          144 
          233 
          377 

 15  rows selected
p
---------
 15 

SQL>