[kba]

I was curious, so I wrote a small program to check it:

The normal distribution is

    1: 24.9940%
    3: 25.0128%
    7: 25.0100%
    9: 24.9832%

The distribution following a prime ending in 1:

    1: 17.0448%
    3: 31.0789%
    7: 32.1018%
    9: 19.7745%

Source: https://gist.github.com/kbadk/71bbb57c9be0d66de156

[redblacktree]

FTA:

> “Every single person we’ve told this ends up writing their own computer program to check it for themselves,” says Kannan Soundararajan, a mathematician at Stanford University in California, who reported the discovery with his colleague Robert Lemke Oliver