Help with graphing Bessel function and its sums

[RickyFlips]

I'm new-ish to HP Prime and hoping someone can help me figure out how to graph a Bessel function and its sums. I've already put about two hours into trying to figure this out on my own using the documentation, built-in help, and Google results, but no joy.

Here's what I've got in the Sequence app:
   

When I click the Plot button, I get this, which obviously isn't correct:
   

My understanding is that, in order to sum the sequence, I have to wrap it inside a function, so here's my attempt at that, which causes the calculator to reboot:
   

Trying this a different way without graphing, I entered it as an expression, but got syntax error:
   

Any help would be very much appreciated!