Easy Peasy Sudoku Advent (14) - Consecutive Sums
(Published on 14. December 2025, 06:00 by Richard)
This sudoku advent calendar contains 24 variants that were included in my Sudoku Variants Series (SVS) but turned out to be too hard to be solved by a wide range of puzzlers. I aim for difficulties of 1-2 stars and have written some general and/or specific hints as well. I hope some players will try the original SVS puzzle #385 after solving the advent version.
Consecutive Sums
In case of a sum of 45, at least the two pairs of digits closest to both borders have to contain consecutive digits.
The 41 clue in C8 indicates that the 4 is not included in any consecutive sum.
Apply classic sudoku rules.
Clues outside the grid indicate the sum of all digits that have at least one consecutive digit as neighbour in the corresponding row or column.
General hint for this type:
Each pair of consecutive digits has an odd sum. An even clue outside the grid indicates an even number of odd digits included in the sums.
There are a lot of sums that can be formed only with one possible combination:3-5-6-7-10-11-13...
At least for the next sums there are only two possible combinations: 9-12-14-16-17
And on the other end of the spectrum large sums can be formed in multiple ways, but the sum of the digits not included in consecutive sums is restricted too: 41-44 (one possibility); 40-42 (two possibilities)
The 9 in R7 has to be attached to the 8, but if you do so on the right side, there is an isolated digit in R7C9.
The 7 in that row has to be attached to a 6, and that must be placed on the left side of the 7, for similar reasons.
Solution code: Row 1
Comments
yesterday, 12:41 by Tws
Hier brauchte ich einige Zeit bis ich die Regel umsetzen konnte. Am Ende kam dann doch ein toller Run heraus! Danke schön für ein weiteres klasse Rätsel!
on 21. December 2025, 05:22 by Richard
Removed one possibility (15) from the list of sums that can be formed only in two ways.
on 20. December 2025, 15:55 by SennyK
Very pleasant to solve, not too hard, thank you!
on 17. December 2025, 20:38 by UnknownDjinn
This was an exquisite puzzle. Not very difficult and it unraveled clearly.
on 16. December 2025, 01:42 by Reina
Solution code doesnt seem to work. Is that row1? Im not german speaking and translation is Line1 and i dont know how that works. Not row1, not column1 works for me
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Reply: Hi Reina, it is indeed row 1. If you click on the English/German flag on top of the page, you can switch from German to English and vice versa. If you are on the English version of the site the solution code is 'Row 1'. On the German version 'Zeile 1'.
But if Row 1 doesn't work, there may be a mistake somewhere...
OP reply: thank you for language advice and thank you for this marvoelous puzzle! There was indeed unintentional consecutive pair that i missed before. Love the whole series so far!
on 15. December 2025, 20:10 by dzamie
A nice, steady burn throughout the solve. Tricky enough that I don't think I'll tackle the harder version, but still a very cool rule!
on 14. December 2025, 20:21 by SKORP17
ziemlich unklare Regel
was ist, wenn keine Summe außerhalb angegeben ist, ist die Summe dann 0 oder irgendein beliebiger Wert
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Reply: Those clues are just not given; can be any number from 0 to 45.
on 14. December 2025, 16:07 by soyorin
Nice puzzle! First time to do this type, but quite enjoyed a lot.
on 14. December 2025, 14:18 by Klausku
Nice puzzle. Very interesting ruleset.
on 14. December 2025, 09:49 by faltenin
Thanks for the hints!
