Starting with polynomial:
P : 63/8*t^5 - 35/4*t^3 + 15/8*t
Extension levels are: 5 16
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Trying to find an order 16 Kronrod extension for:
P1 : 63/8*t^5 - 35/4*t^3 + 15/8*t
Solvable: 1
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Ending with final polynomial:
P : 63/8*t^21 - 123674670581/3171265708*t^19 + 180709480704313/2188173338520*t^17 - 12083075931599/123646781115*t^15 + 6071112915091/85667865492*t^13 - 73112519652907/2249360306094*t^11 + 132291375506969/14088469879548*t^9 - 467353268908967/283726129518675*t^7 + 8441023069733807/52205607831436200*t^5 - 117288300587981/15661682349430860*t^3 + 1112587844447/10441121566287240*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
-------------------------------------------------
The nodes are:
| (-0.99261540453781165524 + 7.0293997895273629809e-363j)  +/-  (7.93e-122, 7.93e-122j)
| (0.15500602137286204479 - 4.5539962243985750155e-365j)  +/-  (9.37e-127, 9.37e-127j)
| (-0.96134856368178933391 + 1.8993599744038170894e-366j)  +/-  (1.86e-121, 1.86e-121j)
| (-0.63087264370021210705 - 7.6130689529566437505e-370j)  +/-  (1.63e-122, 1.63e-122j)
| (0.63087264370021210705 - 1.4688219459228460119e-373j)  +/-  (1.57e-122, 1.57e-122j)
| (0.9061798459386639928 - 3.5254794471864979458e-376j)  +/-  (1.99e-121, 1.99e-121j)
| (0.99261540453781165524 + 1.2033947729233703363e-377j)  +/-  (7.56e-122, 7.56e-122j)
| (-0.9061798459386639928 + 6.1817634662323629304e-382j)  +/-  (1.88e-121, 1.88e-121j)
| (-0.82914919218009739841 + 2.296820905717940758e-382j)  +/-  (1.06e-121, 1.06e-121j)
| (0.96134856368178933391 - 8.0789919099498242938e-380j)  +/-  (1.91e-121, 1.91e-121j)
| (0.73415620079730241944 + 1.639578661304841153e-390j)  +/-  (4.37e-122, 4.37e-122j)
| (0.43678909447140196308 - 4.5272747007724247171e-407j)  +/-  (4.96e-124, 4.96e-124j)
| (-0.43678909447140196308 + 6.6651525543599640019e-413j)  +/-  (4.9e-124, 4.9e-124j)
| (-0.53846931010568309104 - 4.8013109757425793456e-414j)  +/-  (3.75e-123, 3.75e-123j)
| (-1.1479305002424434858e-424 + 1.0748600105107521425e-424j)  +/-  (3.3e-423, 3.3e-423j)
| (0.82914919218009739841 - 6.7209200549896005905e-447j)  +/-  (1.07e-121, 1.07e-121j)
| (0.53846931010568309104 - 8.2254875952908374163e-468j)  +/-  (3.96e-123, 3.96e-123j)
| (-0.15500602137286204479 + 2.4909991128588054707e-474j)  +/-  (9.95e-127, 9.95e-127j)
| (-0.73415620079730241944 - 4.4974325698878285163e-475j)  +/-  (4.21e-122, 4.21e-122j)
| (-0.30384202795433928862 + 7.2385449442633372729e-476j)  +/-  (2.57e-125, 2.57e-125j)
| (0.30384202795433928862 - 1.1347584220595100984e-481j)  +/-  (2.86e-125, 2.86e-125j)
-------------------------------------------------
The weights are:
| (0.018922109385135370112 + 9.3431360084187786892e-363j)  +/-  (7.65e-44, 1.81e-102j)
| (0.15306752425759946796 - 6.61387862918197019e-363j)  +/-  (1.95e-44, 4.61e-103j)
| (0.043459331297916842016 - 1.5999699414813790708e-362j)  +/-  (3.38e-44, 7.99e-103j)
| (0.10072124042701687241 - 2.4715732395584613612e-362j)  +/-  (7.7e-45, 1.82e-103j)
| (0.10072124042701687241 - 5.5267929580024272516e-363j)  +/-  (7.38e-45, 1.75e-103j)
| (0.066547042293159185718 + 5.9534876175600350465e-364j)  +/-  (1.59e-45, 3.76e-104j)
| (0.018922109385135370112 + 6.7135017161134781043e-365j)  +/-  (3.14e-46, 7.42e-105j)
| (0.066547042293159185718 + 1.3045997518449639633e-362j)  +/-  (3.43e-45, 8.1e-104j)
| (0.086910938227872853106 - 1.3698239387292242031e-362j)  +/-  (1.44e-45, 3.41e-104j)
| (0.043459331297916842016 - 2.5657770258440897431e-364j)  +/-  (5.56e-46, 1.31e-104j)
| (0.10167688509672312588 + 2.5863620186221781115e-363j)  +/-  (5.5e-46, 1.3e-104j)
| (0.11939367874949361918 - 8.3582887815656500963e-363j)  +/-  (1.67e-46, 3.96e-105j)
| (0.11939367874949361918 - 2.1376437754855413073e-362j)  +/-  (3.31e-47, 7.84e-106j)
| (0.088182950460129579541 + 2.8260066717026566349e-362j)  +/-  (6.09e-47, 1.44e-105j)
| (0.15595958025586339571 + 7.1987216458487601155e-363j)  +/-  (6.6e-48, 1.56e-106j)
| (0.086910938227872853106 - 1.2324234347997592234e-363j)  +/-  (1.15e-47, 2.71e-106j)
| (0.088182950460129579541 + 8.4183280451450728871e-363j)  +/-  (1.33e-47, 3.14e-106j)
| (0.15306752425759946796 - 9.0312400128810098329e-363j)  +/-  (1.48e-48, 3.53e-107j)
| (0.10167688509672312588 + 1.7227370357460359187e-362j)  +/-  (6.97e-49, 1.65e-107j)
| (0.14313850967702138623 + 1.3062062962257295753e-362j)  +/-  (8.64e-49, 2.06e-107j)
| (0.14313850967702138623 + 7.0047814194154959816e-363j)  +/-  (7.1e-49, 1.59e-107j)
