I spend a lot of time (on my bike) playing with factorization and looking for prime numbers or number patterns. I happened to notice that 115 = 5 * 23 and 118 = 2 * 59 (two primes), while 116 and 117 are both the products of a prime number and a square number (4 * 29 and 9 * 13 respectively). It's meaningless, but I liked how it made a little pyramid pattern.