[ Eq(Derivative(x1, t), (1*k1*(10*k2 - x1)/(1 + k2 + x1 + x2**2) + (-1)*k1*(2*x1 - x2)/(1 + x1 + x2))/k1),
  Eq(Derivative(x2, t), (1*k1*(2*x1 - x2)/(1 + x1 + x2) + (-1)*k1*(x2 - x3)/(1 + x2 + x3 + x4**2) + (-1)*k1*(x2 - x5)/(1 + x2 + x5 + x6**2))/k1),
  Eq(Derivative(x3, t), (1*k1*(x2 - x3)/(1 + x2 + x3 + x4**2) + (-1)*k1*(5*x3 - x4)/(1 + x3 + x4))/k1),
  Eq(Derivative(x4, t), (1*k1*(5*x3 - x4)/(1 + x3 + x4) + (-1)*k1*(10*x4 - k3)/(1 + x4 + k3))/k1),
  Eq(Derivative(x5, t), (1*k1*(x2 - x5)/(1 + x2 + x5 + x6**2) + (-1)*k1*(5*x5 - x6)/(1 + x5 + x6))/k1),
  Eq(Derivative(x6, t), (1*k1*(5*x5 - x6)/(1 + x5 + x6) + (-1)*k1*(10*x6 - k4)/(1 + x6 + k4))/k1),
  Eq(Derivative(x7, t), 0),
  Eq(Derivative(x8, t), 0),
  Eq(Derivative(x9, t), 0) ]