input "Number of rows needed:- "; rowsNeeded

dim colWidth(rowsNeeded)    '    5 rows implies 5 columns

for col=1 to rowsNeeded
    colWidth(col) = len(str$(col + rowsNeeded*(rowsNeeded-1)/2))
next

currentNumber =1

for row=1 to rowsNeeded
    for col=1 to row
        print right$( "  "+str$( currentNumber), colWidth(col)); " ";
        currentNumber = currentNumber + 1
    next
    print
next