Different Outputs

/*Output 1/*

DECLARE
A NUMBER :='&FIRSTNO.';
BEGIN
FOR X IN 1..A
LOOP
FOR Y IN 1..X
LOOP
DBMS_OUTPUT.PUT(Y || ' ');
END LOOP;
DBMS_OUTPUT.NEW_LINE( );
END LOOP;
END;

/*Output 2/*

DECLARE
A NUMBER :='&FIRSTNO.';
BEGIN
FOR X IN 1..A
LOOP
FOR Y IN 1..X
LOOP
DBMS_OUTPUT.PUT(X || ' ');
END LOOP;
DBMS_OUTPUT.NEW_LINE( );
END LOOP;
END;
/

/*Output 3/*

DECLARE
A NUMBER :='&FIRSTNO.';
BEGIN
FOR X IN REVERSE 1..A
LOOP
FOR Y IN 1..X
LOOP
DBMS_OUTPUT.PUT(X || ' ');
END LOOP;
DBMS_OUTPUT.NEW_LINE( );
END LOOP;
END;
/

/*Output 4/*

DECLARE
A NUMBER :='&FIRSTNO.';
BEGIN
FOR X IN REVERSE 1..A
LOOP
FOR Y IN 1..X
LOOP
DBMS_OUTPUT.PUT(X || ' ');
END LOOP;
DBMS_OUTPUT.NEW_LINE( );
END LOOP;
END;
/