The numbers 1, 6, and 7 are natural numbers that follow a specific sequence in mathematics. 1 is the first positive integer and represents unity or a single unit. 6 is the next number, which is the sum of the first three positive integers (1 + 2 + 3) and is also a perfect number, as its divisors (1, 2, 3) sum to itself. 7 is the next integer after 6 and is often considered a lucky number in various cultures. It is also a prime number, meaning it can only be divided by 1 and itself. These numbers are fundamental in various mathematical concepts and everyday counting.