Logic Masters Deutschland e.V.

Here's a diagonal implementation of Sotehr's periodic sums constraint.

• Normal sudoku rules apply.
• The grid is projective:
  • Each edge of the grid is considered to be adjacent/orthogonal to its diametrically opposite edge. (For example, r2c1 is considered orthogonally adjacent to r8c9.)
  • Coloring on the edge indicates this identification.
  • Diagonals wrap around diametrically opposite sides of the grid and reverse their orientation. (For example, a diagonal going through the NW corner of r4c1 would wrap to a diagonal entering r7c9 from its NE corner, and a diagonal going NW through r1c1 turns back on itself going SE through r1c1 itself.)
• Diagonal Periodic Sums:
  • A number outside the grid indicates the sum of the seen cells along the indicated diagonal.
  • Clues see the first cell and every Nth cell after that along the indicated diagonal, where N is the value in the first cell seen from the clue. (For example, if r6c9 is a 2 then the arrow pointing to it sees r6c9, r4c7, r2c5, ... and so on.)
  • A cell seen multiple times is only added once.

Online in Sudokupad

See also:

• a simple motion
• call me a livid pro-funk reject
• the herding party
• hello DubiousMobius
• demasiados bichos
• projective identification