Starting with polynomial:
P : 16*t^4 - 48*t^2 + 12
Extension levels are: 4 15
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Trying to find an order 15 Kronrod extension for:
P1 : 16*t^4 - 48*t^2 + 12
Solvable: 1
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Ending with final polynomial:
P : 16*t^19 - 748536/667*t^17 + 226304664/7337*t^15 - 3155515020/7337*t^13 + 24226003620/7337*t^11 - 9496214910/667*t^9 + 1965071745/58*t^7 - 112008278655/2668*t^5 + 250467132825/10672*t^3 - 83438061525/21344*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: 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
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The nodes are:
| (2.1888080617024303415 + 5.517829349022488652e-447j)  +/-  (1.34e-123, 1.34e-123j)
| (4.0676787766194897745 - 3.2287930448673612671e-458j)  +/-  (2.06e-123, 2.06e-123j)
| (4.8759532376325231043 - 4.0299354168550312789e-472j)  +/-  (5.11e-124, 5.11e-124j)
| (-4.8759532376325231043 - 5.6010630940020478039e-476j)  +/-  (4.5e-124, 4.5e-124j)
| (-4.0676787766194897745 + 2.6531351497904436966e-476j)  +/-  (1.97e-123, 1.97e-123j)
| (3.3862181400001748776 - 9.9523354300922387178e-485j)  +/-  (2.67e-123, 2.67e-123j)
| (-2.7676033562166682643 - 1.2400202414918266183e-487j)  +/-  (2.04e-123, 2.04e-123j)
| (-1.6506801238857845559 - 2.1658461650380890596e-488j)  +/-  (7.68e-124, 7.68e-124j)
| (-3.3862181400001748776 + 7.0222430060833593543e-489j)  +/-  (2.51e-123, 2.51e-123j)
| (2.1600859358757537164e-490 + 1.6364287392998134215e-490j)  +/-  (5.15e-489, 5.15e-489j)
| (1.0392484373427345816 - 6.3207060055455293405e-492j)  +/-  (6.92e-125, 6.92e-125j)
| (0.52464762327529031788 + 1.3327695306415945644e-496j)  +/-  (2.98e-126, 2.98e-126j)
| (-0.52464762327529031788 + 1.1660953083084302793e-495j)  +/-  (2.98e-126, 2.98e-126j)
| (-1.3498998593245308008 + 3.8765802272994389906e-496j)  +/-  (3.93e-124, 3.93e-124j)
| (2.7676033562166682643 - 3.4146366897468488371e-496j)  +/-  (1.98e-123, 1.98e-123j)
| (1.3498998593245308008 - 1.361641001738631449e-497j)  +/-  (3.68e-124, 3.68e-124j)
| (1.6506801238857845559 + 3.9105693872536537719e-503j)  +/-  (7.55e-124, 7.55e-124j)
| (-2.1888080617024303415 - 2.004868141521227354e-510j)  +/-  (1.25e-123, 1.25e-123j)
| (-1.0392484373427345816 - 2.4430172147615896096e-512j)  +/-  (7.62e-125, 7.62e-125j)
-------------------------------------------------
The weights are:
| (0.0026332912577838252915 - 5.2933807404717589569e-449j)  +/-  (1.47e-43, 7.39e-106j)
| (2.6754593145768840665e-08 - 5.0072310311837846406e-453j)  +/-  (1.16e-48, 5.86e-111j)
| (2.4680854113371119705e-11 + 7.1341665107922988608e-455j)  +/-  (3.4e-50, 1.71e-112j)
| (2.4680854113371119705e-11 - 2.7135440691474911501e-455j)  +/-  (6.1e-52, 3.07e-114j)
| (2.6754593145768840665e-08 + 1.5037096681316873798e-453j)  +/-  (9.41e-51, 4.73e-113j)
| (3.808387112574692344e-06 + 1.4302921162302242687e-451j)  +/-  (6.07e-49, 3.06e-111j)
| (0.00015865791200224291336 + 3.6794660108862784261e-451j)  +/-  (4.36e-49, 2.2e-111j)
| (0.018335754268755476046 + 3.0998071439812516695e-449j)  +/-  (4.7e-47, 2.37e-109j)
| (3.808387112574692344e-06 - 3.0719966739550636595e-452j)  +/-  (4.6e-50, 2.31e-112j)
| (0.29618544838856196635 + 1.1435186045191882084e-448j)  +/-  (2.72e-45, 1.37e-107j)
| (0.093677240983887796956 + 2.8163867753518431999e-448j)  +/-  (4.94e-46, 2.48e-108j)
| (0.22434644523122326417 - 1.5340632542729381529e-448j)  +/-  (1.44e-45, 7.22e-108j)
| (0.22434644523122326417 - 9.408399009202199809e-449j)  +/-  (7.11e-46, 3.57e-108j)
| (0.01275205098567983687 - 8.4709781623055163082e-449j)  +/-  (7.7e-47, 3.87e-109j)
| (0.00015865791200224291336 - 3.1508458208019198073e-450j)  +/-  (1.74e-49, 8.73e-112j)
| (0.01275205098567983687 - 3.5732535975721315249e-448j)  +/-  (1.81e-47, 9.08e-110j)
| (0.018335754268755476046 + 2.2116809164761637236e-448j)  +/-  (5.79e-48, 2.91e-110j)
| (0.0026332912577838252915 - 3.3191699265360795014e-450j)  +/-  (1.71e-49, 8.73e-112j)
| (0.093677240983887796956 + 1.0029578244627422396e-448j)  +/-  (4.6e-48, 2.23e-110j)
