Standard Irregular Sudoku rules are in effect, i.e., every row, column, and outlined box must contain the digits 1-9 exactly once each. The grey cells also constitute a single region.
Solution code: The 5th row, then the 9th column (18 digits total).
on 14. September 2021, 16:46 by glum_hippo
added online solving tool tag
on 11. April 2021, 15:49 by MrBeachHut
Very enjoyable. Lovely geometry.
on 20. January 2021, 21:08 by elpadrinoIV
I'm not good or enjoy very much irregular sudoku, but I enjoyed this one and it's quite approachable. Thanks for the puzzle!
on 20. January 2021, 18:07 by panthchesh
Thanks for the puzzle! :)