Starting with polynomial:
P : t^6 - 15*t^4 + 45*t^2 - 15
Extension levels are: 6 14
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Trying to find an order 14 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^20 - 1580233/10630*t^18 + 18492139/2126*t^16 - 1100714877/4252*t^14 + 18003002199/4252*t^12 - 163469220915/4252*t^10 + 794720043117/4252*t^8 - 1891476081495/4252*t^6 + 1837014244065/4252*t^4 - 476939117655/4252*t^2 + 4347968625/4252
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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: 0
  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
-------------------------------------------------
The nodes are:
| (2.5861561128503592152 - 2.119353601097813004e-469j)  +/-  (7.82e-124, 7.82e-124j)
| (-5.8953997181291852999 - 2.498368932719334481e-475j)  +/-  (3.25e-123, 3.25e-123j)
| (-7.0172349364319694865 + 1.7834585090725291782e-482j)  +/-  (9.74e-124, 9.74e-124j)
| (4.1092859793025666241 - 1.3150810126935675437e-483j)  +/-  (4.87e-123, 4.87e-123j)
| (5.8953997181291852999 - 1.5546073023348227504e-492j)  +/-  (3.1e-123, 3.1e-123j)
| (7.0172349364319694865 + 4.1512493577361142169e-496j)  +/-  (9.82e-124, 9.82e-124j)
| (-1.2322910160130311169 - 6.4131730561830241956e-499j)  +/-  (2.76e-125, 2.76e-125j)
| (-0.61670659019259415219 - 1.3487780785936255735e-500j)  +/-  (2.48e-126, 2.48e-126j)
| (0.097250069972428060494 + 2.2921607120958337429e-499j)  +/-  (1.95e-127, 1.95e-127j)
| (-4.9556127485325152627 + 6.4676575943861000309e-501j)  +/-  (5.57e-123, 5.57e-123j)
| (3.3242574335521189524 - 1.0726392304179042592e-505j)  +/-  (2.46e-123, 2.46e-123j)
| (4.9556127485325152627 + 4.6364758062779330445e-506j)  +/-  (5.49e-123, 5.49e-123j)
| (-1.8891758777537106755 - 5.6684186973303883617e-507j)  +/-  (1.72e-124, 1.72e-124j)
| (-4.1092859793025666241 - 1.06896730554561016e-510j)  +/-  (4.32e-123, 4.32e-123j)
| (1.2322910160130311169 + 2.4534401051392847781e-517j)  +/-  (2.52e-125, 2.52e-125j)
| (1.8891758777537106755 - 6.598907868995317679e-517j)  +/-  (1.79e-124, 1.79e-124j)
| (0.61670659019259415219 - 2.775982877582164889e-518j)  +/-  (2.92e-126, 2.92e-126j)
| (-2.5861561128503592152 - 1.0152165952300488737e-516j)  +/-  (8.32e-124, 8.32e-124j)
| (-3.3242574335521189524 + 5.3938101189507525946e-528j)  +/-  (2.21e-123, 2.21e-123j)
| (-0.097250069972428060494 + 5.5536623015697323562e-539j)  +/-  (1.95e-127, 1.95e-127j)
-------------------------------------------------
The weights are:
| (0.010095985080654178925 + 4.6182849862041739091e-471j)  +/-  (2.7e-42, 9.72e-104j)
| (1.1393410819758348156e-08 - 3.2829366344974926345e-476j)  +/-  (1.96e-49, 7.04e-111j)
| (1.0423450108792484403e-11 + 5.3730984585306985287e-478j)  +/-  (6.99e-51, 2.51e-112j)
| (6.9794403591943936003e-05 - 3.7895782928428646439e-473j)  +/-  (1.96e-47, 7.05e-109j)
| (1.1393410819758348156e-08 - 8.4141288284180329224e-476j)  +/-  (1.05e-50, 3.76e-112j)
| (1.0423450108792484403e-11 + 1.1645012881188843639e-477j)  +/-  (2.18e-52, 7.84e-114j)
| (0.11886210945008991277 - 7.7826911958042436716e-471j)  +/-  (9.63e-43, 3.46e-104j)
| (0.19552372342852925967 + 2.9757942108671250565e-470j)  +/-  (1.79e-42, 6.45e-104j)
| (0.12889606437556600666 + 1.4164194772829596884e-469j)  +/-  (8.3e-43, 2.98e-104j)
| (1.641639681587260716e-06 + 7.1387057126449685514e-475j)  +/-  (1.44e-50, 5.17e-112j)
| (0.0012081544070138637274 + 5.5618197999185909668e-472j)  +/-  (1.59e-47, 5.72e-109j)
| (1.641639681587260716e-06 + 2.272186082937417685e-474j)  +/-  (1.09e-49, 3.9e-111j)
| (0.045342515811038977177 + 1.9524354480487075853e-471j)  +/-  (8.31e-47, 2.99e-108j)
| (6.9794403591943936003e-05 - 8.6208199993672691376e-474j)  +/-  (2.08e-50, 7.48e-112j)
| (0.11886210945008991277 + 2.1950336654519564513e-470j)  +/-  (3.1e-46, 1.13e-107j)
| (0.045342515811038977177 - 1.2536649231154904879e-470j)  +/-  (3.55e-47, 1.3e-108j)
| (0.19552372342852925967 - 4.8394539441679120906e-470j)  +/-  (2.47e-46, 9.15e-108j)
| (0.010095985080654178925 - 4.1368273502284365746e-472j)  +/-  (3.45e-49, 1.25e-110j)
| (0.0012081544070138637274 + 6.9456842696813667722e-473j)  +/-  (5.23e-50, 1.86e-111j)
| (0.12889606437556600666 - 1.3137537732965013588e-469j)  +/-  (8.08e-47, 4.13e-108j)
