PL/SQL fibonacci series

PL/SQL program to generate Fibonacci series

DECLARE  

a number;

b number;

c number;

num number;

BEGIN

  num:=&enter;           -- To take input from the user

  a :=0;

  b :=1;

  c :=0;

   for i in 1..num

     LOOP

      dbms_output.put_line(c);

       c :=a+b;

       a :=b;

       b :=c;

    END LOOP;

END;