code: private static double calculateHeightDegrees(int n) {
          double a;
          if (n % 2 == 0)
              a = 0;
          else
              a = -0.5;
          double result = 180 / Math.pow(2, 2.5 * n + a);
          return result;
      }
docs: Returns the height in degrees of the region represented by a geohash of
  length {@code n}.
  
  @param n length of hash
  @return height in degrees of the region represented by a geohash of length {@code n}