[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

maths/leonardo_numbers.py

@@ -1,13 +1,13 @@
 def leonardo_numbers(n: int) -> int:
     """
     Return the n-th Leonardo number.
-    
+
     The Leonardo numbers are a sequence of numbers given by the recurrence:
     L(n) = L(n-1) + L(n-2) + 1
     with initial values L(0) = 1 and L(1) = 1.
-    
+
     Reference: https://en.wikipedia.org/wiki/Leonardo_number
-    
+
     >>> leonardo_numbers(0)
     1
     >>> leonardo_numbers(1)
@@ -31,16 +31,18 @@ def leonardo_numbers(n: int) -> int:
     """
     if not isinstance(n, int) or n < 0:
         raise ValueError("n must be a non-negative integer")
-    
+
     if n == 0 or n == 1:
         return 1
-        
+
     a, b = 1, 1
     for _ in range(n - 1):
         a, b = b, a + b + 1
-        
+
     return b
 
+
 if __name__ == "__main__":
     import doctest
-    doctest.testmod()
+
+    doctest.testmod()