What is cost basis if shares of stock in 2013, when my father gave it to me price per share was $29 & when I sold in 2017, price was $52. Thank you

Your cost basis is actually the lower of the Fair Market Value at the time of the gift (2013) or the price your father paid for the stock, whichever is lower. 

Or, it could be something in between, depending on your situation.  TurboTax has an interview where you can specify that the stock was a gift, enter the FMV and the date of the gift and the donor's basis, and TurboTax will figure out the correct basis to report.