Given k and n, return a list of all the positive integers less than n such that the sum of the kth powers of their individual digits equals the integer itself. For example, with k=3 and n=1000, one of the numbers we would return in the list would be 371, because 371 = 3^3 +7^3 + 1^3 = 27 + 343 + 1. (This problem inspired by Project Euler.)