I am trying to compute the probability of having 4 (or more) consecutive heads in 10 coin tosses. 

I tried using recursion but it led to a complicated expression so i think i did not quite manage. 

I saw similar questions asked here that were solved with difficult approaches, but this problem looks like it could be solved in a couple of lines so I must be doing something wrong.

If anyone could help me understand it or propose a different approach for solving the problem i would be very grateful.

Have a nice day!