System checked as an APSTS(v) with v=31 on {A,B,0,1,...(v-3)} with 
A=v-2, B=v-1, a block AB0, a generic labelling w.r.t. {A,B}, 
and no blocks 0w(w+4) (mod v-2).  155 blocks follow.

   0   1   6
   0   2  11
   0   3  10
   0   4   7
   0   5  14
   0   8  15
   0   9  18
   0  12  19
   0  13  22
   0  16  23
   0  17  26
   0  20  27
   0  21  28
   0  24  25
   0  29  30
   1   2  29
   1   3  27
   1   4  30
   1   5   8
   1   7  21
   1   9  13
   1  10  22
   1  11  20
   1  12  14
   1  15  25
   1  16  24
   1  17  19
   1  18  26
   1  23  28
   2   3   5
   2   4  13
   2   6  22
   2   7  30
   2   8  18
   2   9  16
   2  10  26
   2  12  24
   2  14  23
   2  15  28
   2  17  25
   2  19  27
   2  20  21
   3   4  29
   3   6  30
   3   7  16
   3   8  22
   3   9  11
   3  12  13
   3  14  25
   3  15  19
   3  17  21
   3  18  24
   3  20  28
   3  23  26
   4   5  24
   4   6   8
   4   9  23
   4  10  15
   4  11  17
   4  12  21
   4  14  28
   4  16  26
   4  18  27
   4  19  25
   4  20  22
   5   6  29
   5   7  12
   5   9  26
   5  10  30
   5  11  25
   5  13  19
   5  15  22
   5  16  20
   5  17  23
   5  18  28
   5  21  27
   6   7  25
   6   9  19
   6  10  18
   6  11  21
   6  12  16
   6  13  23
   6  14  15
   6  17  27
   6  20  24
   6  26  28
   7   8  29
   7   9  22
   7  10  20
   7  11  28
   7  13  27
   7  14  26
   7  15  18
   7  17  24
   7  19  23
   8   9  27
   8  10  23
   8  11  30
   8  12  25
   8  13  20
   8  14  21
   8  16  17
   8  19  26
   8  24  28
   9  10  29
   9  12  28
   9  14  30
   9  15  17
   9  20  25
   9  21  24
  10  11  14
  10  12  17
  10  13  24
  10  16  21
  10  19  28
  10  25  27
  11  12  29
  11  13  26
  11  15  24
  11  16  27
  11  18  23
  11  19  22
  12  15  30
  12  18  20
  12  22  23
  12  26  27
  13  14  29
  13  15  21
  13  16  25
  13  17  28
  13  18  30
  14  16  18
  14  17  20
  14  19  24
  14  22  27
  15  16  29
  15  20  26
  15  23  27
  16  19  30
  16  22  28
  17  18  29
  17  22  30
  18  19  21
  18  22  25
  19  20  29
  20  23  30
  21  22  29
  21  23  25
  21  26  30
  22  24  26
  23  24  29
  24  27  30
  25  26  29
  25  28  30
  27  28  29

cycle on {A,B} of length  28
   1   2   7   8  11  12  15  16  19  20
  23  24  27  28  25  26  21  22  17  18
  13  14   9  10   5   6   3   4

 pairs with 0 and differences mod v-2
   1   6      5
   2  11      9
   3  10      7
   4   7      3
   5  14      9
   8  15      7
   9  18      9
  12  19      7
  13  22      9
  16  23      7
  17  26      9
  20  27      7
  21  28      7
  24  25      1