Solution
= Solution
The <birth-death master equation> must include jumps of size two on death. For $n\geq2$,
$$
\boxed{\dot p_n=bp_{n-1}+d(n+2)p_{n+2}-(b+dn)p_n}.
$$
At the boundary states it is
$$
\boxed{\dot p_0=2dp_2+Dp_1-bp_0},
\qquad
\boxed{\dot p_1=bp_0+3dp_3-(b+D)p_1}.
$$