The sequence is:
It's very simple indeed you won't need to do any calculation, but you may need to do a little one, good luck. Yes you may really need to read this hint.
Three things make up it, one of them is the first of Good Boy. A cat tamed the boy. The third one is an acronym relating to computer networks.
It is neither due to Euler, nor by Apery.
Some constant perhaps?
Edit: Hint edited.
Edit2: Ok I may add other hints if you comment something (maybe the problem you're facing or which type of hint should be there).