Double Kakuro by Serkan Yürekli
or solve online (using our beta test of Penpa-Edit tools; note that the dotted circles are just for answer entry and are where the number should be placed in the 2×2 cell. An alternate option with centralized digit entry is here.)
Theme: Unicellular
Author/Opus: This is the 164th puzzle from our contributing puzzlemaster Serkan Yürekli.
Rules: Variation of Kakuro. The gray (2×2) cells are to be filled by a single digit which sits in multiple rows and columns. No digits can repeat within an entry, regardless of if it is in a small or large cell.
Answer String: Enter the values in each white/gray cell in the marked rows from left to right, separating the groups with a comma.
Time Standards (highlight to view): Grandmaster = 3:00, Master = 4:15, Expert = 8:30
Solution: PDF
Note: Follow this link for other Kakuro puzzles. More Kakuro puzzles can be found in Kakuro and Variations by Serkan Yürekli. Kakuro will also be featured in the upcoming The Art of Puzzles 2.
I really liked the use of open space in this one. Thanks!
12:07.