Consider the Markov chain with state space {0, 1, 2, ...} and transition probabilities
p(m, m + 1) = 1/2 (1 - 1/(m + 2)) for m >= 0,
p(m, m - 1) = 1/2 (1 + 1/(m + 2)) for m >= 1,
and p(0, 0) = 1 - p(0, 1) = 3/4. Find the stationary distribution pi. (Hint: Note that this is a birth and death chain and use the observation that
sum_{i=0}^{n} 3/((i + 1)(i + 3)) = 3/2 sum_{i=0}^{n} (1/(i + 1) - 1/(i + 3)) = 3/2 (1 + 1/2 - 1/(n + 2) - 1/(n + 3))
for any n >= 0.)