Starting with polynomial:
P : 8192*t^13 - 319488*t^11 + 4392960*t^9 - 26357760*t^7 + 69189120*t^5 - 69189120*t^3 + 17297280*t
Extension levels are: 13 20
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Trying to find an order 20 Kronrod extension for:
P1 : 8192*t^13 - 319488*t^11 + 4392960*t^9 - 26357760*t^7 + 69189120*t^5 - 69189120*t^3 + 17297280*t
Solvable: 1
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Ending with final polynomial:
P : 8192*t^33 - 19545172279296/12466867*t^31 + 1628479144396800/12466867*t^29 - 78073107472373760/12466867*t^27 + 2399010881583813120/12466867*t^25 - 49825817709706183680/12466867*t^23 + 719024285033233902720/12466867*t^21 - 1042886160012159446400/1780981*t^19 + 7462751998634886074400/1780981*t^17 - 37359372760475726332800/1780981*t^15 + 128653074461500258199400/1780981*t^13 - 296331099225795679944600/1780981*t^11 + 437323559510054761508250/1780981*t^9 - 387936126362667166069500/1780981*t^7 + 377382794865165680716125/3561962*t^5 - 88380880665300855757125/3561962*t^3 + 14942089480824877746375/7123924*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:   31 out of 33
Indefinite weights: 0 out of 33
Negative weights:   2 out of 33
Extension rule has valid weights: 0
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*** EXTENSION WITH INVALID WEIGHTS ***
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