code: private static final void x_to_y2(long10 t, long10 y2, long10 x) {
  		sqr(t, x);
  		mul_small(y2, x, 486662);
  		add(t, t, y2);
  		t._0++;
  		mul(y2, t, x);
  	}
docs: /* Y^2 = X^3 + 486662 X^2 + X
  t is a temporary