Add LeonardoNumber algorithm

[Flonator3000]

Is your feature request related to a problem? Please describe.
Adds LeonardoNumber algorithm.

Describe the solution you'd like
The Leonardo numbers are related to the Fibonacci numbers by below relation:
L(n)=2F(n+1)-1
Given a number n, find n-th Leonardo number.

Describe alternatives you've considered

Additional context

[Flonator3000]

Please assign me this. PR already created.

[github-actions]

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