\\ product of Eisenstein integers
prd(u,v) = {
	(real(u)*real(v) - imag(u)*imag(v)) + (imag(u)*real(v)+real(u)*imag(v)-imag(u)*imag(v))*I;
}

n=-1
emit(p) = {
	my (x=real(p)-imag(p), y=imag(p));
	print (n++ " " y);
}

{
	p = [1];
	for (k=1, 6,
		u = apply(z -> p[#p] + prd(z, 2+I),  p);
		v = apply(z -> u[#u] + prd(z, -1-I), p);
		w = apply(z -> v[#v] + z, p);

		p = concat([p, u, v, w]);
	);

	emit(0);
	apply(emit, p);
}

quit