Currently cant comment on the post since I currently dont have enough reputation so I need to ask my questions through here. Will update or delete once I get more information.

Currently the post dosent give some crucial details:

1. Where are you trying to graph/insert the data? Excel, Python, Google Sheets, Etc. Knowing what system you are using can help narrow down how to best help.
2. Based on what you wrote I assuming X1 = 0 and Y1 = 2, Y2 = -1, Y3 = 1. Any subsequent value can be calculated roughly with the following function: Y(X)=Y[N+1]+Y[N]+Y[N-1]+Y[N-2]...Y[1] X>= 1 Y>=2 If not, can you explain what the equation is meant to do.

Once this is done I (Or someone else) can better help answering the question.