c15h32

from The Collaborative International Dictionary of English v.0.48

Pentadecane \Pen`ta*dec"ane\ (p[e^]n`t[.a]*d[e^]k"[=a]n), n.
   [Penta- + Gr. de`ka ten.] (Chem.)
   A hydrocarbon of the paraffin series, ({C15H32}) found in
   petroleum, tar oil, etc., and obtained as a colorless liquid;
   -- so called from the fifteen carbon atoms in the molecule.
   [1913 Webster]