Starting with polynomial:
P : t^6 - 15*t^4 + 45*t^2 - 15
Extension levels are: 6 11
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Trying to find an order 11 Kronrod extension for:
P1 : t^6 - 15*t^4 + 45*t^2 - 15
Solvable: 1
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Ending with final polynomial:
P : t^17 - 14095/133*t^15 + 566655/133*t^13 - 11071185/133*t^11 + 16019025/19*t^9 - 582703605/133*t^7 + 206140275/19*t^5 - 204491925/19*t^3 + 52212600/19*t
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Computing nodes and weights
  current precision for roots: 53
  current precision for roots: 106
 current precision for weights: 53
Linear system for weights solvable: 1
  current precision for roots: 106
  current precision for roots: 212
 current precision for weights: 106
Linear system for weights solvable: 1
  current precision for roots: 212
  current precision for roots: 424
 current precision for weights: 212
Linear system for weights solvable: 1
Sufficient bits for target precision reached
Positive weights:   17 out of 17
Indefinite weights: 0 out of 17
Negative weights:   0 out of 17
Extension rule has valid weights: 1
-------------------------------------------------
The nodes are:
| (5.118831904069731707 - 1.0437469380871848032e-376j)  +/-  (9.88e-124, 9.88e-124j)
| (6.2656456339047345073 - 2.1660771398527483851e-378j)  +/-  (2.76e-124, 2.76e-124j)
| (2.5705213656867401762 - 2.3171988007727075748e-377j)  +/-  (4.25e-124, 4.25e-124j)
| (3.3242574335521189524 + 4.9870148103586532588e-377j)  +/-  (9.85e-124, 9.85e-124j)
| (4.1660706044187784615 + 3.3246765402391021725e-377j)  +/-  (1.35e-123, 1.35e-123j)
| (0.61670659019259415219 - 5.3036471575303060336e-383j)  +/-  (2.8e-126, 2.8e-126j)
| (-6.2656456339047345073 - 2.1475679676535604253e-393j)  +/-  (3.22e-124, 3.22e-124j)
| (1.2461797481810836967 - 1.7494020198543067264e-399j)  +/-  (2.19e-125, 2.19e-125j)
| (-2.5705213656867401762 + 2.9460792131529042079e-404j)  +/-  (4.4e-124, 4.4e-124j)
| (-1.2461797481810836967 + 1.1384569801831539784e-420j)  +/-  (2.19e-125, 2.19e-125j)
| (-5.118831904069731707 - 6.7264967302369385472e-446j)  +/-  (9.88e-124, 9.88e-124j)
| (-3.3242574335521189524 + 8.9051007338744136874e-473j)  +/-  (9.61e-124, 9.61e-124j)
| (-4.1660706044187784615 - 2.0946287863037611795e-488j)  +/-  (1.37e-123, 1.37e-123j)
| (-1.8891758777537106755 - 4.0961856880598454706e-492j)  +/-  (1.27e-124, 1.27e-124j)
| (1.8891758777537106755 + 7.8548579486391044231e-492j)  +/-  (1.33e-124, 1.33e-124j)
| (1.5980749407224740444e-495 + 5.7530697866009065599e-495j)  +/-  (1.02e-493, 1.02e-493j)
| (-0.61670659019259415219 + 4.1911183233135257932e-502j)  +/-  (2.8e-126, 2.8e-126j)
-------------------------------------------------
The weights are:
| (8.3606736538213735258e-07 + 5.4971412344462746593e-382j)  +/-  (1.75e-47, 3.7e-109j)
| (1.5712128594636582856e-09 - 2.9931645453714661777e-384j)  +/-  (4.77e-49, 1.01e-110j)
| (0.010460290363261914121 + 8.5693083794639359331e-379j)  +/-  (4.47e-44, 9.44e-106j)
| (0.0012650679204111914016 - 6.5089020861225282007e-380j)  +/-  (1.36e-45, 2.86e-107j)
| (6.0523913147315706428e-05 - 1.9351818521351953978e-380j)  +/-  (8.92e-47, 1.88e-108j)
| (0.20546042687468999079 - 2.4868360467046169461e-378j)  +/-  (2.34e-44, 4.95e-106j)
| (1.5712128594636582856e-09 + 1.7156625333469574425e-384j)  +/-  (7.81e-53, 1.65e-114j)
| (0.11655691774481518683 + 2.2048758004059404921e-378j)  +/-  (1.52e-44, 3.22e-106j)
| (0.010460290363261914121 + 8.2117908114935849068e-380j)  +/-  (3.06e-48, 6.46e-110j)
| (0.11655691774481518683 + 8.1915176798736745648e-379j)  +/-  (9.38e-46, 1.98e-107j)
| (8.3606736538213735258e-07 - 8.2316375067813450142e-383j)  +/-  (7e-52, 1.48e-113j)
| (0.0012650679204111914016 - 1.3814304683777635588e-380j)  +/-  (4.47e-50, 9.44e-112j)
| (6.0523913147315706428e-05 + 1.4410015737153046628e-381j)  +/-  (4.3e-51, 9.08e-113j)
| (0.0439003320208236933 - 3.1374560153608873728e-379j)  +/-  (1.06e-48, 2.25e-110j)
| (0.0439003320208236933 - 1.7534838567218286958e-378j)  +/-  (6.46e-49, 1.38e-110j)
| (0.2445912070485449325 + 2.2541828687742160203e-378j)  +/-  (3.36e-48, 6.92e-110j)
| (0.20546042687468999079 - 1.5668456560200442547e-378j)  +/-  (1.96e-48, 3.82e-110j)
