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#680, January 10 - January 16, 2026:
The Weekly 'Unsolvable' Sudoku Puzzle

by Andrew Stuart
WARNING: This is the Weekly 'Unsolvable' Sudoku, rated above 'Extreme'.
This is currently unsolvable by my solver, except perhaps with trial and error strategies.
Using the solver will not help you. (much).

Archive

Each week a new 'unsolvable' will be published and the previous will be accessible here from this archive section. If you like very tough puzzles, these are for you.
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Supporter Members have access to all these puzzles going back to number 1.

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Saturday 10-Jan-2026

... by: Frans Goosens

#680

A7=2 Wrong, Undo calculation
A7=4 ( B7=2 ) Solved,

Total solving time is : 5 sec.
Number of logical steps is : 335

Saturday 10-Jan-2026

... by: Yves

E3=4 Or J5=3

Saturday 10-Jan-2026

... by: Serban

# 680 A8=5 C2=2 F8=8 G7=6 Basics 28

1.Column 7 n=5 e=4 Nc=4 Ns=2 => H7=3 OR B7=2 solve

2. Number 3 n=2 e=7 N=27 Nc=16 Ns=9 => H7=3 OR C9=3 solve
Page created on 03-May-2011, last modified on 30-May-2024.
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