> (%i4) sum(n/(3*n+1)/(2*n+1)^2, n, 1, inf)$ > (%i5) closed_form(%), ratsimp; > (%o5) > -(12*sqrt(3)*log(3)-16*sqrt(3)*log(2)-sqrt(3)*%pi^2+4*%pi)/(8*sqrt(3)) I included this very nice example in the demonstration script for levin (www.bertold.org/levin). Michel