Program to calculate Factorial of number.

declare
v_num number :=#
fact number :=1;
begin
for i in 1..v_num
loop
fact:=fact*i;
end loop;
dbms_output.put_line('fact of '||v_num||' is '||fact);
end;
/

Program to calculate Even or odd Number

declare
n number;
r number :=1;
begin
n:=&number;
for r in 1..n
loop
if mod(r,2)=0 then
dbms_output.put_line('Even No :' || r);
end if;
end loop;
end;