You need not any tables to this end. Mathematica does the job by f[a_, b_] := NSum[1/(k*n*(a*k^2 + b*n^2)), {k, 1, Infinity}, {n, 1, Infinity}] For example, f[Pi,0.1] $0.944319 $ I have stroung doubts concerning a closed-form expression for this sum.