243/242

243/242, otherwise known as the rastma or the neutral third comma, is an 11-limit comma with a value of roughly 7.13912 cents. It is significant in Just Intonation as the amount by which a stack of two 33/32 quartertones falls short of an apotome as well as the difference between 243/128 and 121/64. Tempering it out leads to a form of rastmic temperament. When not tempered out, the rastma behaves much as the 11-limit counterpart to the 5-limit's syntonic comma- a property that becomes especially apparent when one works extensively with 33/32 quartertones.