Plot a one-level deep recurrence relation. In the def structure, u for u_n-1.
from math import * from matplotlib.pyplot import * # EWS 2020-12-26 # define parametric here # u: u(n-1) def w(u): f=sqrt(3*u+1) return f # main routine ui=float(input('initial? ')) n=float(input('n? ')) # build xlist=[0] ylist=[ui] k=0 while k<n: k=k+1 f=w(k) xp=k yp=f xlist.append(xp) ylist.append(yp) # plot routine # set axes ya=min(ylist) yb=max(ylist) axis((0,n,ya,yb)) axis(True) # select color, type color ch="green" # plot points plot(xlist,ylist,color=ch) show()