theorem
  1/2 = 1/2^2 + 1/3^2 + 1/4^2 + 1/6^2 + 1/7^2 + 1/9^2 + 1/12^2 + 1/14^2 +
        1/21^2 + 1/36^2 + 1/45^2 + 1/60^2;
