%N Number of isomers of polychlorinated biphenyls.
%H Author?, <a href="http://wvlc.uwaterloo.ca/biology447/modules/module5/pcbdegradation.htm">Polychlorinated biphenyls</a>.
%H Paul Lee, Jay Lee, Pat Sammon and Ana Kasumovic <a href="http://wvlc.uwaterloo.ca/biology447/modules/intro/assignments/pcb_pjpa.htm">PCB in the Environment</a>
%e There are three isomers with just one chlorine atom in the two phenyl rings combined, so the second term is 3. There are 46 isomers with five chlorine atoms in the two phenyl rings combined.
%A _Parthasarathy Nambi_, Nov 28 2005