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A211172 A Sudoku torus. 1
6, 5, 7, 3, 4, 2, 1, 9, 8, 9, 8, 1, 5, 6, 7, 4, 3, 2, 3, 2, 4, 8, 9, 1, 6, 5, 7, 5, 7, 6, 2, 3, 4, 9, 8, 1, 8, 1, 9, 7, 5, 6, 3, 2, 4, 2, 4, 3, 1, 8, 9, 5, 7, 6, 7, 6, 5, 4, 2, 3, 8, 1, 9, 1, 9, 8, 6, 7, 5, 2, 4, 3, 4, 3, 2, 9, 1, 8, 7, 6, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The sequence is a listing for a Sudoku grid:
6 5 7 3 4 2 1 9 8
9 8 1 5 6 7 4 3 2
3 2 4 8 9 1 6 5 7
5 7 6 2 3 4 9 8 1
8 1 9 7 5 6 3 2 4
2 4 3 1 8 9 5 7 6
7 6 5 4 2 3 8 1 9
1 9 8 6 7 5 2 4 3
4 3 2 9 1 8 7 6 5
No two diagonally adjacent elements are the same. If the grid is rolled into a cylinder either way, this is still true making a 'Sudoku torus'.
This extra information can be used to construct puzzles that use 'no diagonal' logic.
The two lexicographical Sudoki in the cross-references have one internal diagonal each and several external diagonals.
LINKS
Mathworld, Sudoku
Wikipedia, Sudoku
EXAMPLE
If a puzzle has say:
|x
5|
___|x
then x cannot be 5.
CROSSREFS
Cf. A107739.
Cf. A114288, A112454 (lexicographic grids).
Sequence in context: A195786 A201330 A089826 * A152149 A338287 A365927
KEYWORD
nonn,fini,full,tabf
AUTHOR
Jon Perry, Jan 31 2013
STATUS
approved

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Last modified May 18 15:50 EDT 2024. Contains 372664 sequences. (Running on oeis4.)