[ Eq(Derivative(x1, t), (1*k3*k4*k5**k6/(k5**k6 + x4**k6) + (-1)*k3*k8*x1 + (-1)*k3*k45*x1/(k46 + x1))/k3),
  Eq(Derivative(x2, t), (1*k3*k7*x1 + (-1)*k3*k9*x2/(k10 + x2) + (-1)*k3*(k11*x2 - k12*x4) + (-1)*k3*k59*x2 + 1*k3*k70*x3/(k71 + x3))/k3),
  Eq(Derivative(x3, t), (1*k3*k9*x2/(k10 + x2) + (-1)*k3*k35*x3 + (-1)*k3*k60*x3/(k61 + x3) + (-1)*k3*k70*x3/(k71 + x3))/k3),
  Eq(Derivative(x4, t), (1*k3*(k11*x2 - k12*x4) + (-1)*k3*(k43*x13*x4 - k44*x16) + (-1)*k3*k62*x4/(k63 + x4) + (-1)*k3*k69*x4 + 1*k3*k72*x14/(k73 + x14))/k3),
  Eq(Derivative(x5, t), (1*k3*k13*x6 + (-1)*k3*k15*x5/(k16 + x5) + (-1)*k3*(k26*x5*x9 - k27*x11) + (-1)*k3*k52*x5 + 1*k3*k74*x7/(k75 + x7))/k3),
  Eq(Derivative(x6, t), ((-1)*k3*k14*x6 + 1*k3*k37*x4**k38/(k39**k38 + x4**k38) + (-1)*k3*k47*x6/(k48 + x6))/k3),
  Eq(Derivative(x7, t), (1*k3*k15*x5/(k16 + x5) + (-1)*k3*k17*x7/(k18 + x7) + (-1)*k3*k54*x7 + (-1)*k3*k74*x7/(k75 + x7))/k3),
  Eq(Derivative(x8, t), (1*k3*(3/2 + (9/5 - 3/2)*ceiling(sin(pi*t/12 + 1/1000)/2))*x4**k19/(k20**k19 + x4**k19) + (-1)*k3*k42*x8 + (-1)*k3*k49*x8/(k50 + x8))/k3),
  Eq(Derivative(x9, t), (1*k3*k21*x8 + (-1)*k3*k24*x9/(k25 + x9) + (-1)*k3*(k26*x5*x9 - k27*x11) + (-1)*k3*k51*x9 + 1*k3*k76*x10/(k77 + x10))/k3),
  Eq(Derivative(x10, t), ((-1)*k3*k22*x10/(k23 + x10) + 1*k3*k24*x9/(k25 + x9) + (-1)*k3*k53*x10 + (-1)*k3*k76*x10/(k77 + x10))/k3),
  Eq(Derivative(x11, t), (1*k3*(k26*x5*x9 - k27*x11) + (-1)*k3*k28*x11/(k29 + x11) + (-1)*k3*(k32*x11 - k33*x13) + (-1)*k3*k56*x11 + 1*k3*k81*x12/(k82 + x12))/k3),
  Eq(Derivative(x12, t), (1*k3*k28*x11/(k29 + x11) + (-1)*k3*k30*x12/(k31 + x12) + (-1)*k3*k55*x12 + (-1)*k3*k81*x12/(k82 + x12))/k3),
  Eq(Derivative(x13, t), (1*k3*(k32*x11 - k33*x13) + (-1)*k3*k40*x13/(k41 + x13) + (-1)*k3*(k43*x13*x4 - k44*x16) + 1*k3*k78*x15/(k79 + x15) + (-1)*k3*k80*x13)/k3),
  Eq(Derivative(x14, t), ((-1)*k3*k36*x14 + 1*k3*k62*x4/(k63 + x4) + (-1)*k3*k64*x14/(k65 + x14) + (-1)*k3*k72*x14/(k73 + x14))/k3),
  Eq(Derivative(x15, t), ((-1)*k3*k34*x15 + 1*k3*k40*x13/(k41 + x13) + (-1)*k3*k57*x15/(k58 + x15) + (-1)*k3*k78*x15/(k79 + x15))/k3),
  Eq(Derivative(x16, t), (1*k3*(k43*x13*x4 - k44*x16) + (-1)*k3*k66*x16 + (-1)*k3*k67*x16/(k68 + x16))/k3) ]