What exactly is a "number include 24 bits"?
This sets 4 elements to 1 and 20 to 0:
v = zeros(1, 24);
v(randperm(24, 4)) = 1;
What is the wanted output?
result = bin2dec('0' + v)
% or
result = v * power(2, 0:23).'
Instead of creating the sum using the dot product, you can use the indices replied by randperm directly:
result = sum(2 .^ (randperm(24, 4) - 1));
I hope this was not a homework question. Otherwise it will be hard for you to submit your own solution now. But you participate in this forum for 6 years now, such that I assume that you are not in the learning phase anymore.
