The first Project Euler problem - Multiples of 3 and 5 - is stated as follows. Find the sum of all the multiples of 3 or 5 below 1000.

```
let sum =
// Generate a list with the numbers from 1 to 999.
[ 1..999 ]
// Filter out the multiples of 3 and 5.
|> List.filter (fun n -> n % 3 = 0 || n % 5 = 0)
// Sum the values.
|> List.sum
printfn "%i" sum
```