Christmas puzzle: find the total

On the first day of Christmas, my true love gave to me
a partridge in a pear tree

Most of us are familiar with the Twelve Days of Christmas song, in which some unnamed person showers another with gifts, some extravagant (ten lords a-leaping? Seriously?) and some quite valuable (5 gold rings! They will have to be sold to pay for the maintenance of the lords, maidens, cows, etc.).  But how many people know how many presents the giftee had on the 3rd day, or the 7th day, or the 12th day? Do you?

Your mission, should you choose to accept it, is to find out how many cumulative gifts the giftee had on the 3rd day, on the 7th day, and on the 12th day. 

The first person to send the correct answer via email to lskinner@pvcc.edu on Wednesday, December 18th, 2013 will win a big chocolate bar. Please include your name, your student ID or Blackboard user name, your email address, and how you arrived at the answer. The first sender will be determined by the time stamp on the email. 

Emails sent before Wednesday, December 18th, will not be considered.