Starting with polynomial:
P : 231/16*t^6 - 315/16*t^4 + 105/16*t^2 - 5/16
Extension levels are: 6 15
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Trying to find an order 15 Kronrod extension for:
P1 : 231/16*t^6 - 315/16*t^4 + 105/16*t^2 - 5/16
Solvable: 1
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Ending with final polynomial:
P : 231/16*t^21 - 5205313449/70709920*t^19 + 14289790791591/89448048800*t^17 - 53308908835107/277288951280*t^15 + 1126298183287221/8041379587120*t^13 - 254450630417893/4020689793560*t^11 + 11958624144649/685344851175*t^9 - 1164763374231093/420344842054000*t^7 + 9423837253467/42034484205400*t^5 - 1187724569941/168137936821600*t^3 + 6211503831/168137936821600*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:
| (-0.9973240486058117504 - 2.5930018832659274269e-369j)  +/-  (2.14e-121, 2.14e-121j)
| (0.93246951420315202781 - 2.0855665663712943839e-366j)  +/-  (3.18e-121, 3.18e-121j)
| (-0.93246951420315202781 - 8.8595254415533425631e-370j)  +/-  (3.05e-121, 3.05e-121j)
| (-0.86361570851789323889 + 4.105434455230444319e-370j)  +/-  (1.36e-121, 1.36e-121j)
| (0.97722740884937972953 + 3.2694922286377688564e-367j)  +/-  (3.96e-121, 3.96e-121j)
| (0.53290119180335118279 - 1.4173814543564860837e-370j)  +/-  (9.68e-124, 9.68e-124j)
| (0.9973240486058117504 - 8.6152537751316900346e-370j)  +/-  (2.29e-121, 2.29e-121j)
| (-0.97722740884937972953 - 8.3428109999134996316e-377j)  +/-  (4.1e-121, 4.1e-121j)
| (-0.53290119180335118279 - 1.0235934478379371207e-377j)  +/-  (7.97e-124, 7.97e-124j)
| (0.86361570851789323889 + 4.7903487520373537021e-381j)  +/-  (1.52e-121, 1.52e-121j)
| (0.7724087312063641925 - 6.5443446775324406284e-403j)  +/-  (3.71e-122, 3.71e-122j)
| (2.5512630424244307708e-424 + 2.2376114119723594386e-424j)  +/-  (7.13e-423, 7.13e-423j)
| (-0.39081014757983207619 + 2.3911473507110956855e-437j)  +/-  (6.87e-125, 6.87e-125j)
| (-0.7724087312063641925 - 2.4303206380608849912e-443j)  +/-  (3.9e-122, 3.9e-122j)
| (0.080302367445227604052 + 2.1231216199042803253e-451j)  +/-  (1.78e-127, 1.78e-127j)
| (0.66120938646626451366 - 7.1029635564692305532e-464j)  +/-  (8.02e-123, 8.02e-123j)
| (0.23861918608319690863 - 5.0656715906575623802e-477j)  +/-  (3.48e-126, 3.48e-126j)
| (-0.080302367445227604052 - 4.3790309406466431219e-487j)  +/-  (1.78e-127, 1.78e-127j)
| (-0.66120938646626451366 + 2.0267169936228189225e-489j)  +/-  (7.48e-123, 7.48e-123j)
| (-0.23861918608319690863 - 7.36495209481122278e-491j)  +/-  (3.64e-126, 3.64e-126j)
| (0.39081014757983207619 - 4.0078758111435310394e-488j)  +/-  (7.34e-125, 7.34e-125j)
-------------------------------------------------
The weights are:
| (0.0086983671280073386246 + 1.6469191311163579437e-368j)  +/-  (8.46e-42, 4.77e-100j)
| (0.057037399996813026225 + 5.0294740200626809939e-367j)  +/-  (1.79e-42, 1.01e-100j)
| (0.057037399996813026225 + 7.077625162409688654e-368j)  +/-  (2.94e-42, 1.66e-100j)
| (0.080376360846976511752 - 9.4701148785647301774e-368j)  +/-  (1.02e-42, 5.78e-101j)
| (0.032328132174560814281 + 1.8058301269244716643e-366j)  +/-  (9.4e-43, 5.3e-101j)
| (0.13578662105536490092 + 9.1399922634300825035e-367j)  +/-  (1.03e-43, 5.81e-102j)
| (0.0086983671280073386246 - 6.8419514292803982516e-367j)  +/-  (4.56e-43, 2.57e-101j)
| (0.032328132174560814281 - 4.6578448928685255548e-368j)  +/-  (1.08e-42, 6.1e-101j)
| (0.13578662105536490092 + 2.5028924838638529549e-367j)  +/-  (2.42e-44, 1.37e-102j)
| (0.080376360846976511752 - 2.4111680475122541706e-366j)  +/-  (6.97e-44, 3.93e-102j)
| (0.10164279085310497473 + 1.3374512186252971626e-366j)  +/-  (2.33e-44, 1.31e-102j)
| (0.00039563385400636417699 + 4.4654427919645531726e-366j)  +/-  (6.4e-46, 3.61e-104j)
| (0.14778020542646738717 - 3.9520877949595212574e-367j)  +/-  (6.05e-46, 3.41e-104j)
| (0.10164279085310497473 + 1.2682878423807477474e-367j)  +/-  (1.16e-45, 6.51e-104j)
| (0.15993737371758115287 - 3.1094103968880816938e-366j)  +/-  (3.92e-46, 2.21e-104j)
| (0.12027399275275740422 - 1.0144639447901156403e-366j)  +/-  (2.2e-46, 1.24e-104j)
| (0.15594093912136330712 + 1.2678703871748002309e-366j)  +/-  (7.27e-47, 4.1e-105j)
| (0.15993737371758115287 - 2.6174994591982503186e-366j)  +/-  (9.03e-47, 5.12e-105j)
| (0.12027399275275740422 - 1.7384473904128151655e-367j)  +/-  (1.04e-47, 5.9e-106j)
| (0.15594093912136330712 + 7.5224581541074792433e-367j)  +/-  (1.73e-47, 9.88e-106j)
| (0.14778020542646738717 - 9.630803364405591926e-367j)  +/-  (8.64e-48, 4.57e-106j)
