Ohhh good answer. Okay let me see...
Well if I run 16 LEDs @ 3.5V = 56V but the LM317, but the LM317 needs at least 3.25V to work properly so I will need to remove 1 LED.
So, I would need to run 15 LEDs @ 3.5V = 52.5V with 5.5V remaining. This would output 5.5V*0.7A = 3.85W which would require a heatsing which could dissipate (60-20)/3.85 = 10.4 degrees per Watt.
(Max. Heatsink Thermal Resistance = (60 - AmbientTemp) / Power)
The LM317 would still require a 1.8ohms 1W resistor to maintain a current of .7A.
Is this correct?