Henon attractor

X11(width=8,height=8)
plot(0,0,xlim=c(-2,2),ylim=c(-1,1))
x=0;y=0;X=0;Y=0
n=10000 # How many points.
for(i in 1:n)
{
x1=x
x=1+y-1.39*(x^2)
y=0.3*x1
points(x,y,pch=".")
X[i]=x;Y[i]=y
}