There is now weekly Tapa Variation Contest. I have created some of the Tapa puzzles for the practice of this contest, which I am posting it now.
"Math Tapa" Instructions:
Paint some squares black to create a continuous wall. Number/s in a square indicate the length of black cell blocks on its neighbouring cells. If there is more than one number in a square, there must be at least one white cell between the black cell blocks. Painted cells cannot form a 2x2 square or larger. There are no wall segments on cells containing numbers.
The expressions means that there is more than one number in the cell, and the result of that operation on them equals the given number. (Example: +4 could be 1+3, or 2+2, or 1+1+2 or 1+1+1+1).