I noticed that GosperSum can easily do telescoping sums. load(zeilberger); limit(GosperSum(1/(k*(k+1)),k,1,n),n,inf); Result: 1 Of course this does not work for sum(1/(3*k+1)^2+1/(3*k+2)^2,k,0,inf) which is 8/9*zeta(2)=4/27*%pi^2. Michel