From David Jenkins
Jacob Aron discusses patterns in prime numbers (19 March, p 12). This prompted me to wonder whether the patterns would persist if you considered the last two digits in a prime number rather than the last one. For instance, 1097 is a prime number: what are the chances of the following prime ending in 97?
I checked all numbers up to 10 million and found 664,579 prime numbers. Of those I found one case of a prime ending in 11 being followed by another one, no cases at all of a 77 being followed by another 77 but 3577 cases of 01 being followed by 07. These are just a few examples. When you plot them out as a scattergram, a complex pattern emerges.
Carlton, Bedfordshire, UK
