Is it 2400 Watts = 20A x 120V?
20AX120V = 2400 VA, not 2400 W unless the load is almost purely resisitive like a electrical heater. For inductive load you have to apply a power factor, that could be anywhere between 0.7 to 0.9, for audio equipment, probably around 0.8 so 2400 VA will be more like 2400X0.8W = 1920W
My equipment would be
Receiver Yamaha RX-A3060 = 230 Watts?
Outlaw 5000 Amp = 1500 Watts
Projector = 353 Watts
Blu Ray Player = 24 Watts
Sub (RMS = 250 Watts) Max = 1000 Watts 4 Ohms.
If you are using the A3060 as a prepro only, it will probably draw between 80 to 120W, but this is just an educated guess.
The Outlaw 5000 may draw 1500W at rated output, but for normal use in you HT room, assuming your room is not very big and you don't listen at above reference level, it will most likely be hoovering around 100 to 80W to 120W average with peaks up to 1,000W, a little more, or less, most likely less.
Can I have all of this on this one circuit?
Yes.
I also have some home theater seats that draw power too.
What all do I have to consider?
If you have a large screen (say 60" and over) TV, it could draw some significant power, check the manual but I would guess around 200W for LCD type and 300W or more for Plasma. A 20A outlet is still adequate even a Plasma large screen is plugged in.