t = sum_(i=1..5) g_i(t)^6,  g_i(t) = c_i0 + c_i1 t + ... (centre values to 25 digits; '*' = exact fixed value)
g_1:  c_10 = (0.47) + (0) i *;   c_11 = (0.5601849918690139516007124) + (-0.6593169156883769065715738) i  ;   c_12 = (0.4667006778727324255903046) + (-0.1544131665785225390118245) i  
g_2:  c_20 = (0.5067965160002524219687461) + (-0.4507873592394767122940674) i  ;   c_21 = (-0.14) + (-0.11) i *;   c_22 = (-0.04572431117349248594189194) + (0.6212345021921143299093502) i  
g_3:  c_30 = (0.02479303004275997333551948) + (0.004182265667877549305654249) i  ;   c_31 = (0.4366677240396274419867712) + (1.009811080825474921537132) i  ;   c_32 = (0.2836124508114724237500476) + (-0.3419186203820585308321054) i  
g_4:  c_40 = (0.4295679466996107539803346) + (0.3679820721088560305101564) i  ;   c_41 = (-0.7727671132872886420540823) + (0.09594234412487102075042818) i  ;   c_42 = (-0.3243093140405644604806548) + (0.6194647434145670819993167) i  
g_5:  c_50 = (0.636172218505460998943826) + (-0.1103560598134072070747164) i  ;   c_51 = (0.5071017419659262628392209) + (0.5660364632875395801870778) i  ;   c_52 = (0.5256308834744990525793796) + (-0.4040370621192783418146035) i  
homogeneous form: x*y^11 = sum_i G_i(x,y)^6,  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):
  4.8e-61, 1.7e-60, 1.7e-60, 1.8e-60, 4.6e-60, 1.0e-59, 3.8e-60, 1.3e-59, 8.2e-60, 1.1e-59, 4.8e-60, 2.8e-60, 6.4e-61
