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# Meissel Mertens constant

```ruby
var sum = 0
1e7.each_prime {|p|
    with (1f/p) {|t|
        sum += (log(1 - t) + t)
    }
}
say sum+Num.EulerGamma
```

#### Output:

```
0.26149721577767111119422410228297206467931376306
```