Add custom power and equation functions with call counter

[protagonist9]

This file defines a custom power function and a custom equation function that performs calculations based on provided integer parameters. It also includes a function to count calls to it.

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Checklist

• I have read the [CONTRIBUTING]
• I have performed a self-review of my own code
• I have run the code locally and it works as expected
• I have commented my code, particularly in hard-to-understand areas

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