Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n = 1 for the first term. 1, -4, 16

Mike wants to make meatloaf. his recipe uses a total of 8 pounds of meat. if he uses a 3 to 1 ratio of beef to pork, how much pork will he use? enter your answer as a mixed number in simplest terms.