This is an interesting one. Raavad ratio, 7-8-11-13, holding like Rashi where the first three winds and last three winds per Chulya are white, but per in between each set of knots. The rest of the winds in the middle are Techeiles, which is 7 (-6) + 8 (-6) + 11 (-6) + 13 (-6). Winds are done Sephardi style. The result is that, in terms of Techeiles winds, you end up with 1-2-5-7 Techeiles winds in the middle, adding up to 15 Techeiles winds, and 24 white winds.