The problem is that you are reversing the string a few times. The following will do: (defun base8 (n) (let ((t8 (truncate n 8)) (m8 (mod n 8))) (if (= t8 0) (list m8) (append (base8 t8) (list m8))))) EDIT Here's a solution without append, using a helper function.
So, the average weight for a healthy, human kidney is 0.26-0.30 pounds. (approx.) The average weight for a healthy, human kidney is 120-140 grams. 1 pound= 453.59237 grams. So, the average weight for a healthy, human kidney is 0.26-0.30 pounds. (approx.) The average weight for a healthy, human kidney is 120-140 grams. 1 pound= 453.59237 grams. So, the average weight for a healthy, human kidney is 0.26-0.30 pounds.
InfoPlease explains that human skin weighs between  8 to 10 pounds in normal adults, with around 22 square feet of area. The skin is the largest organ in the body in terms of weight and area. One of the smallest organs in the body, the pineal gland, weighs around 0.2 gram, or 0.007 ounce. The pineal gland is in the center of the brain, according to Kids Discover. The parathyroid is between 0.004 and 0.006 ounce, or 0.12 to 0.18 gram.