Enter one or more numbers from 1 to 9 into each cell. Within a cell, no number appears more than once. Cells that have at least one common number cannot touch each other, not even diagonally. The clue numbers indicate the sum of all entered numbers in the respective cells.
(Rules and example from WPC 2019 IB)
History of the puzzle
Invented by Lại Văn Đức Thịnh (Vietnam) in 2017 as a (late) submission for Puzzle Innovations Contest, a pre-event of WPC 2017.
The name refers to integer partition in number theory.