Complete the analogy 4 : 80 :: 7 : ? by finding the rule that turns the first number of a pair into the second.

Cube the number and add its square: $4\times 4\times 4=64,4\times 4=16$ and 64 + 16 = 80. For 7 this gives 343 + 49 = 392. The trap 350 is 343 + 7, adding the number itself instead of its square; 294 is 343 − 49, subtracting where the rule adds; and 441 is 343 + 98, adding twice the square. None of the three survives the first pair, where the same three steps give 68, 48 and 96 in place of 80.