C23H48

from The Collaborative International Dictionary of English v.0.48

Trikosane \Tri"ko*sane\, n. [Pref. tri- + Gr. ? twenty.] (Chem.)
   A hydrocarbon, {C23H48}, of the methane series, resembling
   paraffin; -- so called because it has twenty-three atoms of
   carbon in the molecule.
   [1913 Webster]