CIRCULANT GRAPHS: number of sets S = -S with each label
   N    sets       Q       R       P       M       ?
   2       2       0       2       0       0       0  
   3       2       0       2       0       0       0  
   4       4       4       0       0       0       0  
   5       4       2       2       0       0       0  
   6       8       6       2       0       0       0  
   7       8       2       6       0       0       0  
   8      16       8       8       0       0       0  
   9      16       4      12       0       0       0  
  10      32      16      16       0       0       0  
  11      32       2      30       0       0       0  
  12      64      32      32       0       0       0  
  13      64       2      62       0       0       0  
  14     128      32      96       0       0       0  
  15     128      16     112       0       0       0  
  16     256      64     192       0       0       0  
  17     256       2     254       0       0       0  
  18     512     128     384       0       0       0  
  19     512       2     510       0       0       0  
  20    1024     256     768       0       0       0  
  21    1024      32     992       0       0       0  
  22    2048     128    1920       0       0       0  
  23    2048       2    2046       0       0       0  
  24    4096     768    3328       0       0       0  
  25    4096      16    4080       0       0       0  
  26    8192     256    7936       0       0       0  
  27    8192     128    8064       0       0       0  
  28   16384    2048   14336       0       0       0  
  29   16384       2   16380       0       2       0  
  30   32768    2640   30128       0       0       0  
  31   32768       2   32766       0       0       0  
  32   65536    4096   61440       0       0       0  
  33   65536     128   65408       0       0       0  
  34  131072    1024  130048       0       0       0  
  35  131072     176  130896       0       0       0  
  36  262144   20992  241152       0       0       0  
  37  262144       2  262140       0       2       0  
  38  524288    2048  522240       0       0       0  
  39  524288     256  524032       0       0       0  
  40 1048576   37120 1011456       0       0       0  
  41 1048576       2 1048572       0       2       0  
  42 2097152   37184 2059968       0       0       0  
  43 2097152       2 2097150       0       0       0