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This is a place chosen to make available some ideas (on puzzles, patterns, etc)
that seemed unsuitable for posting in a Forum, but some people may find interesting.
For difficult puzzles, possible solutions will not be shown (only hints).
For other puzzles, the solution wil be hidden so that a serious attempt can be made
without direct access to a solution.
(hopefully this will make the puzzles more interesting for newcomers)
(Guidelines for using this site here)
(useful to look up for the meaning of some unfamiliar concept)
I propose this Sudoku-X puzzle to be solved manually.
(generated and displayed with Sudoku6Explainer)
After lots of basics
,---------------------------------,
6 | 25 234 1456 | 1456 1346 36 |
5 | 156 34 1456 | 1456 2 1356 |
|----------------+----------------|
4 | 123 6 13 | 45 1345 2345 |
3 | 135 24 45 | 26 13 1236 |
|----------------+----------------|
2 | 4 1 26 | 3 56 256 |
1 | 36 5 236 | 124 146 14 |
'---------------------------------' X
a b c d e f
Update 1 (Aug 4, 2026)
This puzzle is solvable in one step!
Using the diagonal a1-f6, there is an
ALS-xz move that removes (6)i3, (6)d56,
,----------------------------------,
6 | 25 234 1456 | 145-6 1346 36 |
5 | 156 34 1456 | 145-6 2 1356 |
|----------------+-----------------|
4 | 123 6 13 | 45 1345 2345 |
3 | 135 24 45 | 26 13 123-6|
|----------------+-----------------|
2 | 4 1 26 | 3 56 256 |
1 | 36 5 236 | 124 146 14 |
'----------------------------------' X
a b c d e f
solving the puzzle.
I propose this (tough!) Sudoku-X puzzle to be solved manually.
(generated and displayed with Sudoku6Explainer)
After basics
,---------------------------------------,
6 | 35 1235 4 | 125 6 1235 |
5 | 135 2356 256 | 1245 234 12345 |
|-------------------+-------------------|
4 | 2 34 1 | 346 5 346 |
3 | 345 3456 56 | 234 1234 1234 |
|-------------------+-------------------|
2 | 6 1245 3 | 125 24 1245 |
1 | 145 1245 25 | 12356 1234 23456 |
'---------------------------------------' X
a b c d e f
Update 1 (Aug 4, 2026)
Using the pattern of 4s, there is a fish
that removes (4)e4 [no placement].
,---------------------------------------,
6 | 35 1235 4 | 125 6 1235 |
5 | 135 2356 256 | 1245 234 12345 |
|-------------------+-------------------|
4 | 2 34 1 | 346 5 346 |
3 | 345 3456 56 | 234 123 1234 |
|-------------------+-------------------|
2 | 6 1245 3 | 125 24 1245 |
1 | 145 1245 25 | 12356 1234 23456 |
'---------------------------------------' X
a b c d e f
The next step is the hardest one for this puzzle.
Created: February 12, 2024
Contact: sudo.jco.br@gmail.com