35/27
35/27 |0 -3 1 1>
449.2746 cents
35/27, the semi-diminished fourth, is the interval between 9/7 and 5/3. It is about 449.3 cents in size and 351/350 flat of 13/10. Tempering out 351/350 leads to chords such as the ratwolf triad, a tempered 1-6/5-20/13.