Starting with polynomial:
P : 8*t^3 - 12*t
Extension levels are: 3 20
-------------------------------------------------
Trying to find an order 20 Kronrod extension for:
P1 : 8*t^3 - 12*t
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 8*t^23 - 435401548/466119*t^21 + 6984086690/155373*t^19 - 60312139755/51791*t^17 + 922682751235/51791*t^15 - 17221241659335/103582*t^13 + 195859892055555/207164*t^11 - 1318771477098075/414328*t^9 + 9887794220979675/1657312*t^7 - 18448838678845575/3314624*t^5 + 13826157508738575/6629248*t^3 - 2510039001444975/13258496*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
Positive weights:   23 out of 23
Indefinite weights: 0 out of 23
Negative weights:   0 out of 23
Extension rule has valid weights: 1
-------------------------------------------------
The nodes are:
| (-1.6912351602255462682 + 1.9276685072696192483e-476j)  +/-  (8.35e-124, 8.35e-124j)
| (3.7269906560721637973 - 8.6177066578780486253e-481j)  +/-  (3.52e-122, 3.52e-122j)
| (-5.7198395688765504553 - 2.9743728765513408749e-489j)  +/-  (3.31e-123, 3.31e-123j)
| (-3.1843031534006097697 + 3.614871085113287848e-490j)  +/-  (2.54e-122, 2.54e-122j)
| (3.1843031534006097697 + 4.9165774348164865523e-495j)  +/-  (2.31e-122, 2.31e-122j)
| (0.77597218954639109598 - 9.7824511773704340673e-501j)  +/-  (1.73e-125, 1.73e-125j)
| (-3.7269906560721637973 - 1.6438530497513456103e-502j)  +/-  (3.81e-122, 3.81e-122j)
| (-4.9521146218744377125 + 3.0158894351180912437e-507j)  +/-  (1.55e-122, 1.55e-122j)
| (4.9521146218744377125 - 2.0580947293492245404e-509j)  +/-  (1.5e-122, 1.5e-122j)
| (-2.1719717344653489638 + 3.6389243878407409761e-509j)  +/-  (3.43e-123, 3.43e-123j)
| (0.36057682725790650245 + 1.8972367731659153352e-513j)  +/-  (1.74e-126, 1.74e-126j)
| (1.6912351602255462682 + 3.3569828748940282757e-514j)  +/-  (7.7e-124, 7.7e-124j)
| (-4.3084174913056160681 - 4.7045137022960464807e-514j)  +/-  (3.16e-122, 3.16e-122j)
| (-1.2247448713915890491 + 3.7405543090039439092e-519j)  +/-  (1.32e-124, 1.32e-124j)
| (4.3084174913056160681 + 1.6007341742010251406e-519j)  +/-  (3.26e-122, 3.26e-122j)
| (1.2247448713915890491 + 2.2752370822816990406e-522j)  +/-  (1.27e-124, 1.27e-124j)
| (5.7198395688765504553 - 9.8642861233878242886e-528j)  +/-  (3.34e-123, 3.34e-123j)
| (-2.6683040524758297406 + 3.3609361768297984783e-527j)  +/-  (1.13e-122, 1.13e-122j)
| (-0.77597218954639109598 + 1.8785280650099302178e-533j)  +/-  (1.67e-125, 1.67e-125j)
| (-0.36057682725790650245 - 1.1365094793310077818e-532j)  +/-  (1.74e-126, 1.74e-126j)
| (2.1719717344653489638 + 2.9792281031016862048e-533j)  +/-  (3.65e-123, 3.65e-123j)
| (1.9778203809461240391e-537 + 1.0247402698380280348e-537j)  +/-  (5.12e-536, 5.12e-536j)
| (2.6683040524758297406 - 5.3622652955869549117e-541j)  +/-  (1.33e-122, 1.33e-122j)
-------------------------------------------------
The weights are:
| (0.015299987104727462419 + 6.6028964131534293059e-478j)  +/-  (1.26e-38, 6.77e-99j)
| (2.9283548821055862411e-07 + 1.1138538116525218125e-481j)  +/-  (1.09e-46, 5.88e-107j)
| (3.0754180585143364472e-15 + 1.0050160919712870047e-485j)  +/-  (9.42e-51, 5.07e-111j)
| (1.1756902744931743466e-05 + 2.9887131060850479526e-480j)  +/-  (1.39e-45, 7.5e-106j)
| (1.1756902744931743466e-05 - 9.1525668741882774539e-481j)  +/-  (1.55e-46, 8.33e-107j)
| (0.13480533118065524373 + 6.8425109379030243857e-478j)  +/-  (3.58e-41, 1.93e-101j)
| (2.9283548821055862411e-07 - 2.964529007275203676e-481j)  +/-  (3.62e-47, 1.95e-107j)
| (8.6941663855970540721e-12 - 7.6163233582828623984e-484j)  +/-  (6.01e-50, 3.24e-110j)
| (8.6941663855970540721e-12 + 3.7384543662686971084e-484j)  +/-  (7.21e-52, 3.88e-112j)
| (0.0024611269891439376996 + 1.9444889207006099292e-478j)  +/-  (6.71e-45, 3.61e-105j)
| (0.19263250755855154045 - 1.4970865384731157e-477j)  +/-  (4.79e-43, 2.58e-103j)
| (0.015299987104727462419 + 8.7194627004466551953e-479j)  +/-  (6.16e-45, 3.31e-105j)
| (2.9721548441947746391e-09 + 2.0137150710886279735e-482j)  +/-  (5.12e-49, 2.76e-109j)
| (0.057764313554567933236 - 1.6421918903013455371e-477j)  +/-  (8.48e-44, 4.56e-104j)
| (2.9721548441947746391e-09 - 8.7842376674413284789e-483j)  +/-  (1.09e-50, 5.88e-111j)
| (0.057764313554567933236 - 2.6271336018802361856e-478j)  +/-  (5.24e-45, 2.82e-105j)
| (3.0754180585143364472e-15 - 5.4631842651839065118e-486j)  +/-  (7.62e-54, 4.11e-114j)
| (0.0002305912622569605921 - 2.4025493759772388139e-479j)  +/-  (2.24e-47, 1.21e-107j)
| (0.13480533118065524373 + 1.8444850661161551807e-477j)  +/-  (3.26e-45, 1.8e-105j)
| (0.19263250755855154045 - 2.3084361064790797852e-477j)  +/-  (2.29e-45, 1.27e-105j)
| (0.0024611269891439376996 - 2.4197201206423933733e-479j)  +/-  (6.08e-48, 3.28e-108j)
| (0.19358817926202338715 + 2.2806972588217663836e-477j)  +/-  (5.62e-46, 3.59e-106j)
| (0.0002305912622569605921 + 5.3846526774416344469e-480j)  +/-  (1.19e-48, 6.29e-109j)
