D E F

         | 1 2 3 |
         | 2 3 4 |
         | 3 4 5 |
   ---------------------
A  1 2 3 | 4 5 6 | 7 8 9
B  2 3 4 | 5 6 7 | 8 9 1
C  3 4 5 | 6 7 8 | 9 1 2
   ---------------------
         | 7 8 9 |
         | 8 9 1 |
         | 9 1 2 |

Notation:
Letter of row + steps to the right/down

For example:
Sequence - A1

would result in:

           D E F

         | 1 2 3 |
         | 2 3 4 |
         | 3 4 5 |
   ---------------------
A  2 3 4 | 5 6 7 | 8 9 1
B  2 3 4 | 5 6 7 | 8 9 1
C  3 4 5 | 6 7 8 | 9 1 2
   ---------------------
         | 7 8 9 |
         | 8 9 1 |
         | 9 1 2 |