1 | initial version |

Hello,

There are various solutions. To generate the list of numbers of the form 7abc, you can use one of:

```
sage: numbers0 = range(7000,8000)
sage: numbers1 = [7000 + x for x in range(1000)]
sage: numbers2 = [7000 + a*100 + b*10 + c for a in range(10) for b in range(10) for c in range(10)]
```

Then you can check divisibility the very same way you did. But note that there is a faster way since x is a multiple of **7** if and only if **x+7** is a multiple of 7. So once you find one, you only need to go 7 by 7.

Is that ok ?

Vincent

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