def outer(self, P, n) :
		""" outer product on the curve, between a point and a scalar """
		if n == 0:
			return Point(0, 1)
		Q = self.outer(P, n//2)
		Q = self.inner(Q, Q)
		if n & 1:
			Q = self.inner(Q, P)
		return Q
 outer product on the curve, between a point and a scalar 
recipes/Python/579102_ed25519/recipe-579102.py