n  n-th row of A187769   ... in  binary                  row length
  --  --------------------- ------------------------------- ----------
   0  {0}                   {0}                                      1
   1  {1}                   {1}                                      1
   2  {2}                   {10}                                     1
   3  {3}                   {11}                                     1
   4  {4}                   {100}                                    1
   5  {5,6}                 {101,110}                                2
   6  {7}                   {111}                                    1
   7  {8}                   {1000}                                   1
   8  {9,10,12}             {1001,1010,1100}                         3
   9  {11,13,14}            {1011,1101,1110}                         3
  10  {15}                  {1111}                                   1
  11  {16}                  {10000}                                  1
  12  {17,18,20,24}         {10001,10010,10100,11000}                4
  13  {19,21,22,25,26,28}   {10011,10101,10110,11001,11010,11100}    6
  14  {23,27,29,30}         {10111,11011,11101,11110}                4
  15  {31}                  {11111}                                  1