t = sum_(i=1..4) g_i(t)^5,  g_i(t) = c_i0 + c_i1 t + ... (centre values to 25 digits; '*' = exact fixed value)
g_1:  c_10 = (0.61) + (0) i *;   c_11 = (0.7485551526772891537589774) + (-2.332476701707796385342052E-93) i  ;   c_12 = (-0.4969158600467956739593953) + (9.441973371982434271889082E-93) i  
g_2:  c_20 = (-0.6015985488651934698904578) + (-2.375989870666593251134245E-93) i  ;   c_21 = (0.7555844907567809788813389) + (-3.876257652373387143126582E-93) i  ;   c_22 = (0.4869814442853430906469169) + (-8.177760504213753401166308E-93) i  
g_3:  c_30 = (-0.05004956086299881622745524) + (0.3299314893237855402910496) i  ;   c_31 = (-0.2551307739278631003124537) + (-0.1850216470009281533916186) i  ;   c_32 = (-0.613965322399797527376098) + (0.2012452055819655112327249) i  
g_4:  c_40 = (0.2344198089905819905406764) + (0.2375017880833937842080402) i  ;   c_41 = (0.09765213643366454581428222) + (-0.2996477630717563378495927) i  ;   c_42 = (0.6149973437139759976103748) + (-0.198068970573304463466012) i  
homogeneous form: x*y^9 = sum_i G_i(x,y)^5,  G_i = sum_j c_ij x^j y^(2-j)
coefficients of sum g_i^k - t at the centre (exact, shown as floats):
  1.2e-61, 9.0e-62, 1.6e-61, 1.4e-60, 1.7e-60, 3.5e-60, 1.8e-60, 4.2e-61, 1.2e-60, 9.8e-61, 2.4e-61
