updating DIRECTORY.md

DIRECTORY.md

@@ -541,8 +541,8 @@
   * [Basic Maths](maths/basic_maths.py)
   * [Binary Exp Mod](maths/binary_exp_mod.py)
   * [Binary Exponentiation](maths/binary_exponentiation.py)
-  * [Binary Exponentiation 2](maths/binary_exponentiation_2.py)
   * [Binary Exponentiation 3](maths/binary_exponentiation_3.py)
+  * [Binary Multiplication](maths/binary_multiplication.py)
   * [Binomial Coefficient](maths/binomial_coefficient.py)
   * [Binomial Distribution](maths/binomial_distribution.py)
   * [Bisection](maths/bisection.py)
@@ -557,8 +557,7 @@
   * [Decimal Isolate](maths/decimal_isolate.py)
   * [Decimal To Fraction](maths/decimal_to_fraction.py)
   * [Dodecahedron](maths/dodecahedron.py)
-  * [Double Factorial Iterative](maths/double_factorial_iterative.py)
-  * [Double Factorial Recursive](maths/double_factorial_recursive.py)
+  * [Double Factorial](maths/double_factorial.py)
   * [Dual Number Automatic Differentiation](maths/dual_number_automatic_differentiation.py)
   * [Entropy](maths/entropy.py)
   * [Euclidean Distance](maths/euclidean_distance.py)