For this Sudoku Variants Project I have planned to publish a unique Sudoku variant every week.
Double Decker Sandwich
Inspiration for this type comes from Sudonym.
Solve online in
I will see how long it takes before I am running out of ideas.
Apply classic sudoku rules.
Clues on the left and above the grid are regular sandwich clues; they indicate the sum of the digits that are placed between the digit 1 and the digit 9 in the corresponding row or column.
Clues on the right and below the grid are also sandwich clues, but they indicate the sum of the digits placed between the digit 2 and the digit 8 in the corresponding row or column.
Sudokupad (no answer check)
Sudokupad (with answer check)
or
Penpa+.
Solution code: Column 4
on 17. January 2026, 12:58 by wuc
Cool refreshing variant. Great fun thx.
on 16. January 2026, 14:49 by Sudonym
Nice puzzle...appreciate the acknowledgement above, thank you. :)
on 16. January 2026, 13:55 by Franjo
Thank you very much for creating and sharing another perfect introduction of an interesting idea.
on 16. January 2026, 12:49 by Ragna
Fun puzzle! Thank you. :-)
on 16. January 2026, 11:13 by flutchman
Very well crafted, there seems to be not nearly enough information to solve the puzzle. I also appreciate the 1-9 & 2-8 reminders in the NW and SE corners.
on 16. January 2026, 08:38 by wuc
Cool refreshing variant. Great fun thx.
on 16. January 2026, 08:00 by Piatato
Smooth and fun!