Rename variables to be more descriptive

Author: prakritim01

maths/leonardo_numbers.py

@@ -1,13 +1,16 @@
+"""
+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
+"""
+
+
 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)
@@ -35,14 +38,14 @@ def leonardo_numbers(n: int) -> int:
     if n == 0 or n == 1:
         return 1
 
-    a, b = 1, 1
+    previous, current = 1, 1
     for _ in range(n - 1):
-        a, b = b, a + b + 1
+        previous, current = current, previous + current + 1
 
-    return b
+    return current
 
 
 if __name__ == "__main__":
     import doctest
 
-    doctest.testmod()
+    doctest.testmod()