Logic Masters Deutschland e.V.

Ever since Sotehr introduced the concept of periodic sums [1] [2] it went straight to my to-dög list.

• Normal sudoku rules apply.
• Doppel-Dög loop:
  • Draw an orthogonal non-branching closed loop that doesn't cross or touch itself, not even diagonally.
  • The loop "starts" at the cell marked with the dog and is considered to be oriented in the direction indicated by the arrow (i.e. r5c7 and r5c8 are in the loop).
  • A cell on the loop with a digit D will have a value equal to the digit D steps away along the loop in the orientation given by the arrow.
  • Cells not on the loop will have a value equal to the digit in them.
• Adjacent digits (not values) along the loop must have a difference of at least 5.
• Clues outside the grid are Periodic Sum clues: A number outside the grid indicates the sum of the first and every Nth value in the row or column, where N is the value in the first cell seen from the clue.
• Cells marked with a circle are not part of the loop and have a digit equal to the count of the, up to 8, neighboring loop cells.
• Cells joined by a ball have the same value.

Online in Sudokupad

More Doppel-Dögs:

• can i pet that dog!? / please, can we keep him!?
• did you say walkies!?
• a walk in the park
• yo tenía diez perritos
• nopil nahual
• Convection Currents by ThePedallingPianist
• Doppel-Dög Sandwich by phil_the (hat)
• Tentropic Terrier by Scojo