Starting with polynomial:
P : t^8 - 28*t^6 + 210*t^4 - 420*t^2 + 105
Extension levels are: 8 19
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Trying to find an order 19 Kronrod extension for:
P1 : t^8 - 28*t^6 + 210*t^4 - 420*t^2 + 105
Solvable: 1
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Ending with final polynomial:
P : t^27 - 812337437/2980019*t^25 + 93544974150/2980019*t^23 - 11120302213950/5534321*t^21 + 4822995895784025/60877531*t^19 - 122775907799391975/60877531*t^17 + 2058945737509419300/60877531*t^15 - 22810657893583801500/60877531*t^13 + 12686440347454676625/4682887*t^11 - 5280959871173476125/425717*t^9 + 14472656643666296250/425717*t^7 - 21427406694775383750/425717*t^5 + 14093817146384810625/425717*t^3 - 2605992197474649375/425717*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:   25 out of 27
Indefinite weights: 0 out of 27
Negative weights:   2 out of 27
Extension rule has valid weights: 0
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*** EXTENSION WITH INVALID WEIGHTS ***
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