WolframAlpha computational knowledge AI
sum from i = 2 to infinity (sum j from 0 to (i-2) ((1-p-q)^(i-j-2)(p)*(1-q)^(j)(q) + (1-q-p)^(i-j-2)(q)*(1-p)^j*p)*i), p=1/x , q=1/y