Does Raymer's installed engine equation include the weight of the pylon?
No, it doesn't include the pylon. If you think about it, the engine is installed on the pylon, which is part of the aircraft's fuselage or wing structure and not part of the engine. 

You can see what I mean by watching this video of the replacement of an engine on an American Airlines 777.

Raymer's equation does include the nacelle and other auxiliary equipment installed on the engine.