In 2 steps you can use two 2-digit oddagons for 27.
You can also replace 27 by a,b and see that r3c8, r8c6, r8c9, r9c8 and r9c9 see both digits:
- Code: Select all
*-------------------------------------------------------*
| 5 1 #a | #b 3 9 | 8 4 6 |
| #b 9 3 | 6 8 4 | 1 5 #a |
| 6 4 8 | 1 5 #a | 239 3-27 237 |
|---------------+----------------+----------------------|
| 9 7 6 | 34 2 8 | 5 13 134 |
| 3 2 4 | 5 9 1 | 7 6 8 |
| 1 8 5 | 34 7 6 | 239 239 234 |
|---------------+----------------+----------------------|
| 8 5 1 | #a 4 3 | 6 #b 9 |
| 4 6 #b | 9 1 5-27 | 23 8 35-27 |
| #a 3 9 | 8 6 257 | 4 1-27 15-27 |
*-------------------------------------------------------*