There are charts, fomulas and "science". Then there's reality.

Charts and formulas provide a rough guideline or starting place, but you need to use the pressure that's right for not only the wight nd section, but the flex properties of your tires and the rod conditions.

As a rule, more pressure means lower rolling resistance on smooth pavements, but can actually increase rolling resistance on rough pavement and over bumps because of the rear vector of the tire impact. Higher pressure also means lower traction, and less comfort. OTOH overly low pressure will mean high drag and pinch flats or dented rims.

Experiment and find the best balance for your needs. Start any place on the low side based on the charts, and increase pressure incrementally by 5#s or so over time, until you feel the effects of excess pressure -- harsh ride, skittish handling, serious rebound on bumps -- then drop back 5#s to where you feel the balance was right. BTW- don't forget to keep front tire pressure lower than rear.