Ah, I didn’t realize you wanted to animate renderability. Here’s a couple options:
You can animate the renderability of just one of your objects (remember that animating the “eyeball” icon only affects the object in the 3D viewer – you need to animate the “camera” icon for it to be hidden in the render! I like to have one window with the Display–> “Only Render” option enabled, so I can keep track of what will render and what will not.). Then, in the dope sheet, go to the “Action Editor”. Your keyframes will have a name like “cubeAction.001” or something. You can rename this to something more clear, like “KeyRenderable” etc. Then you can select all your other objects, choosing the animated one last, ctrl+L and choose link to “Animation Data.” Now all the objects share the same keyframes!
This approach only works if the only thing you’re animating is the renderability. If you’re animating the position as well, for instance, then all your objects will start moving in exactly the same place, etc, which is bad. Linking animation data doesn’t exist in AE, really – it’s as though the keyframes exist on their own, and now all the objects inherit them. In AE you need a specific layer that drives the properties; in blender the keyframes are independent of any specific object.
A SECOND OPTION is to use drivers. This is a bit more like AE expressions. You choose one object and animate its renderability. Then you right click on the renderability icon of another object and choose “Add Driver.” That makes it purple (instead of yellow/green for regular keyframing). In the Graph editor, you can choose “Drivers” instead of the “F-Curve Editor” and if you press N to view the properties, you’ll find a section called “Drivers” for your driver.
In that section, delete the modifier, change the type to “Averaged Value” (or “Sum” works as well – actually any of the types except for “Scripted Expression” will work for this). Set your variable type to be “Single Property” in the drop-down box, and then underneath that choose the object you’re already keyframing.
Those steps are pretty straightforward once you’ve done it a couple times. This is the only tricky step: the Path. To find what to put in this section, hover your mouse over the renderability icon; it reads “Python: Object.hide_render” – you don’t need “Object” because you’ve already defined the object; all you need is the last part: “hide_render”. So write hide_render in the Path section. And your “AE expression” is complete!
I’m not sure if there’s a way to copy just drivers to the other objects. Again, if all you have on an object is a driver, then you can select all, ctrl_L and copy animation data – which also copies drivers. Then everything goes purple. (But it will still mess with any other keyframes you’ve set as well, so beware!)