Repeating numbers in a sequence as n=many times as the number

Question

I gave myself a small puzzle, to try to get the numbers 1-5 repeating as many times as their values: 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5
My first attempt was quite simple. But i do not understand the results. Can someone explain to me why these are the results?
SQL> SELECT
  2     Rownum,
  3     A
  4  FROM
  5     (SELECT Rownum A FROM Dual CONNECT BY Rownum <= 5)
  6  CONNECT BY
  7     Rownum <= A;
    ROWNUM          A
         1          1
         2          2
         3          3
         4          4
         5          5
         6          2
         7          3
         8          4
         9          5
9 rows selected.

Answer 1

Another way, probably what i was originally trying to figure out. It's backwards, but it relies on rownum, and the complete processing of the TABLE:
SQL> SELECT
  2     A
  3  FROM
  4     (SELECT Rownum A FROM Dual CONNECT BY Rownum <= 5)
  5  CONNECT BY
  6     Rownum BETWEEN  ((A * A) - A) /2 + 1 AND ((A * A) + A) / 2 - 1;
         A
         1
         2
         2
         3
         3
         3
         4
         4
         4
         4
         5
         5
         5
         5
         5
15 rows selected.
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