DECLARE

V_Area_Id NUMBER;

BEGIN

  SELECT MAX(T.Area_Id)+10 INTO V_Area_Id FROM T_PM_TankArea T;

  if V_Area_Id is null THEN select 1 into V_Area_Id from dual;

    END IF;

EXECUTE IMMEDIATE

'create sequence S_PM_TankArea

minvalue 1

maxvalue 9999999999999999999999999999

start with ' || V_Area_Id

|| 'increment by 1

nocache';

end;

/