information theory, find entropy given Markov chain
You can make the golloowing set of equations, where s1 - the probability of being in s1 state:

s1 = 0.25s1 + 0.5s2
...
s1+s2+s3=1


I don't know the theory, but think that entropy of each state can be computed as follows:

e1 = - 0.25*log(0.25) - 0.75*log(0.75)


with overall entropy given already computed probability and entropy of each state

e = e1*s1 + e3*s3 + e3*s3


I don't know what H(...) means.