What's the probability of getting at least 3 concecutive heads in 10 tosses of a coin?

If I toss a coin 10 times, what's the probability of getting at least 3 heads concecutively? The results of the other 7 tosses do not matter. Please show me the formula as well as the result, thank you!
Thanks for the reply.
Since there is a myriad of possibilities for the other 7 tossses,I don't think simply listing the possibilities would work because there is too much work involved.


Active Member
It's not an easy problem. It looks like there is no formula. To get 3 out of 10 you first have to work out 3 out of 9 and 2 out of 9 and combine them.