>>>>On the 1st day of Xmas, my true love gave to me:
>>>>1 item
>>>>On the 2nd day of Xmas, my true love gave to me:
>>>>2 items + 1 item
>>>>On the 3rd day of Xmas, my true love gave to me:
>>>>3 items + 2 items + 1 item
>>>>.
>>>>.
>>>>On the n-1 day of Xmas, my true love gave to me:
>>>>n-1 items + n-2 items + ... + 1 item
>>>>On the nth day of Xmas, my true love gave to me:
>>>>n items + n-1 items + ... + 1 item
>>>>
>>>>How many total items did my true love give to me, as a function of n?
>>>
>>>Number of gifts = gifts(n)
>>>
>>>
>>>FUNCTION gifts(n)
>>>lnReturn = 0
>>>FOR I = 1 TO n
>>> FOR H = 1 TO I
>>> lnReturn = lnReturn + H
>>> ENDFOR
>>>ENDFOR
>>>RETURN lnReturn
>>>
>>>
>>>not arithmetic, but it works
>>
>>Er, yes, but there is an elegant mathematical solution that even a computer would like! (no looping involved)
>
>
>Maybe it can be : Gifts = (n+1) * (n/2) ??

Um, no, we've seen that one earlier...that's not the cumulative sum for all the days, that's only one day...