67 GHz

I’ve made a few references to 67 in puzzles, including just a couple of puzzles ago. I’m doing it again. 67 67 67. Why not? Sometimes you see a waveform-like shape and a need for a couple of given digits, so why pick them at random when 67 are right there?

Note: This is puzzle 100 for 2026, numbered as I created them.

Rules:
Normal Sudoku rules apply.
Adjacent digits on solid green lines differ by at least five.
Digits on each hollow pink line form a non-repeating set of consecutive digits in any order.

Estimated difficulty: 1.5 out of 5