The square-full numbers in an interval
M. N. Huxley, Ognian Trifonov · Mathematical Proceedings of the Cambridge Philosophical Society · 1996
A positive integer is square-full if each prime factor occurs to the second power or higher. Each square-full number can be written uniquely as a square times the cube of a square-free number. The perfect squares make up more than three-quarters of the sequence {si} of square-full numbers, so that a pair of consecutive square-full numbers is a pair of consecutive squares at least half the time, with