Adam Forsythe-Cheasley

Prime Birthdays

The idea of prime Birthdays came to me whilst I was contemplating why we deem some of our Birthdays more important than others. For example in this country, we deem the following Birthdays as “special”:
13, 16, 18, 21, 30, 40, 50, etc.

Of course I can see why 18 might be cause for a bigger celebration than usual and some of the others make some sense, but why 30? Why 40? This led me to the idea of assigning significance to a Birthday based on some other property of the number. The obvious choice was prime numbers. The beauty of this system is that when you are young, and Birthdays are a big deal, you have many prime birthdays. As you get older, you have fewer and fewer “special” Birthdays, as shown by the prime number theorem.

Prime numbers less than 100

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97