Four 5 ohm resistance can be connected in 10 different way as shown below.was there any way we can generalize this concept and find a formula to calculate the number of possible ways of connecting resistors if the number of resistors was given.

(5||5)+(5||5)=5 ohms

(5||5||5)+5=6.666 ohms

5+5+5+5 = 20 ohms

5||5||5||5 = 1.25 ohms

5||(5+5+5)= 3.75 ohms

5+5+(5||5)=12.5 ohms

(5+5)||(5+5)=5 ohms

(5+5)||5||5 = 2 ohms

((5+5)||5)+5= 8.333 ohms

((5||5)+5)||5= 3 ohms

(5||5)+(5||5)=5 ohms

(5||5||5)+5=6.666 ohms

5+5+5+5 = 20 ohms

5||5||5||5 = 1.25 ohms

5||(5+5+5)= 3.75 ohms

5+5+(5||5)=12.5 ohms

(5+5)||(5+5)=5 ohms

(5+5)||5||5 = 2 ohms

((5+5)||5)+5= 8.333 ohms

((5||5)+5)||5= 3 ohms