\[(1) \ \ x_{(n+1)} = x_{(n)}^2 + e.\]
x <- rep(NA, 1000) e = rnorm(1000,0,1) x[1] <- e[1] for (n in 1:999) { x[n+1] = x[n]^2%%100 + e[n+1] }
plot(x[-1000], x[-1], col = rainbow(16))