Floyd's triangle   lists the natural numbers in a right triangle aligned to the left where

 the first row is   1     (unity)
 successive rows start towards the left with the next number followed by successive naturals listing one more number than the line above.


The first few lines of a Floyd triangle looks like this:

 1
 2  3
 4  5  6
 7  8  9 10
11 12 13 14 15



Task

 Write a program to generate and display here the first   n   lines of a Floyd triangle. 
(Use   n=5   and   n=14   rows).
 Ensure that when displayed in a mono-space font, the numbers line up in vertical columns as shown and that only one space separates numbers of the last row.


 
/* REXX *************************************************************** 
* Parse Arg rowcount                                                    
* 12.07.2012 Walter Pachl  - translated from Python                     
**********************************************************************/ 
Parse Arg rowcount                                                      
col=0                               
ll=''                               /* last line of triangle         */ 
Do j=rowcount*(rowcount-1)/2+1 to rowcount*(rowcount+1)/2               
  col=col+1                         /* column number                 */ 
  ll=ll j                           /* build last line               */ 
  len.col=length(j)                 /* remember length of column     */ 
  End                                                                   
Do i=1 To rowcount-1                /* now do and output the rest    */ 
  ol=''                                                                 
  col=0                                                                 
  Do j=i*(i-1)/2+1 to i*(i+1)/2     /* elements of line i            */ 
    col=col+1                                                           
    ol=ol right(j,len.col)          /* element in proper length      */ 
    end                                                                 
  Say ol                            /* output ith line               */ 
  end                                                                   
Say ll                              /* output last line              */ 
 