The given sandwich sums are either zero, or they are a square number (indicated by a *).
Cages sum to a square number.
The crust of a sandwich (1 or 9) is never in a cage.
Normal Sudoku rules apply. Cages will sum to the calculated value and do not have repeated digits. Little killer diagonals sum to the given value.
Solve the puzzle online at F-Puzzles
Solution code: Enter the digits for row 3 followed by the digits of row 8.
on 20. June 2021, 10:56 by PrimeWeasel
Nice solve. 2 stars for me. Took me 25 minutes with a slight interruption of my cat demanding food
-- thanks. I developed a second, which is slightly harder, puzzle ID 0006OS
on 11. June 2021, 22:55 by Timwi
The puzzle text does not clarify whether the * clues can also have a sandwich sum of 0 (after all 0 is also a square number).
It turns out that even if you allow that, the puzzle is still unique (but much harder).
on 11. June 2021, 14:15 by Goofy
I personally rated it average difficulty, but thats a personal opinion. The puzzle was really smooth from the beginning to the end. It was fun to figure out where the 1s and 9s go and what the cages will add up to. Thank you for the experience^^