PLSQL block to display following

Write a PLSQL block to display following:

 1
2 2
3 3 3
4 4 4 4

Program:

DECLAREV VARCHAR2(20);

BEGIN

FOR I IN 1..4

LOOP

FOR J IN 1..I

LOOP

V:=V||' '||I;

END LOOP;

DBMS_OUTPUT.PUT_LINE(V);

V:=NULL;

END LOOP;

END;

/

Output:

1

2 2

3 3 3

4 4 4 4