levels   bits  Zeckendorf     CSD  binary
     16   4.00       1.562   1.750   2.000
     21   4.39       1.810   1.810   2.000
     55   5.78       2.364   2.418   2.745
    144   7.17       2.917   2.771   3.444
    377   8.56       3.469   3.326   4.119
    987   9.95       4.022   3.800   4.904
   4181  12.03       4.851   4.426   5.959
  17711  14.11       5.681   5.092   6.924