# Armstrong Numbers

An [Armstrong number](https://en.wikipedia.org/wiki/Narcissistic_number) is a number that is the sum of its own digits each raised to the power of the number of digits.

For example:

- 9 is an Armstrong number, because `9 = 9^1 = 9`
- 10 is *not* an Armstrong number, because `10 != 1^2 + 0^2 = 1`
- 153 is an Armstrong number, because: `153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153`
- 154 is *not* an Armstrong number, because: `154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190`

Write some code to determine whether a number is an Armstrong number.

## Running the tests

To run the tests, run the command `dotnet test` from within the exercise directory.

## Autoformatting the code

F# source code can be formatted with the [Fantomas](https://github.com/fsprojects/fantomas) tool.

After installing it with `dotnet tool restore`, run `dotnet fantomas .` to format code within the current directory.

## Further information

For more detailed information about the F# track, including how to get help if
you're having trouble, please visit the exercism.io [F# language page](http://exercism.io/languages/fsharp/resources).

## Source

Wikipedia [https://en.wikipedia.org/wiki/Narcissistic_number](https://en.wikipedia.org/wiki/Narcissistic_number)