Starting with polynomial:
P : t^16 - 120*t^14 + 5460*t^12 - 120120*t^10 + 1351350*t^8 - 7567560*t^6 + 18918900*t^4 - 16216200*t^2 + 2027025
Extension levels are: 16 23
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Trying to find an order 23 Kronrod extension for:
P1 : t^16 - 120*t^14 + 5460*t^12 - 120120*t^10 + 1351350*t^8 - 7567560*t^6 + 18918900*t^4 - 16216200*t^2 + 2027025
Solvable: 1
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Ending with final polynomial:
P : t^39 - 265156989870445/517583353637*t^37 + 60440795944927665/517583353637*t^35 - 1160684062907266755/73940479091*t^33 + 102832387408357757700/73940479091*t^31 - 6357534990615583645860/73940479091*t^29 + 283317919004477132414100/73940479091*t^27 - 9271446808777613896659300/73940479091*t^25 + 224921346094866122225543250/73940479091*t^23 - 4055942418136064219829161250/73940479091*t^21 + 54196987585233036110199806250/73940479091*t^19 - 531956833819080554467616591250/73940479091*t^17 + 3778492655502392241903566962500/73940479091*t^15 - 18991889528363942573598978262500/73940479091*t^13 + 65377944725878348263616429012500/73940479091*t^11 - 146796379320773639404873768342500/73940479091*t^9 + 198930385082023356722484470821875/73940479091*t^7 - 142422541931580126074411975296875/73940479091*t^5 + 42617326845917264694121427934375/73940479091*t^3 - 3785124500229339318122368171875/73940479091*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: 0
  current precision for roots: 212
  current precision for roots: 424
 current precision for weights: 212
Linear system for weights solvable: 1
  current precision for roots: 424
  current precision for roots: 848
 current precision for weights: 424
Linear system for weights solvable: 1
Sufficient bits for target precision reached
Positive weights:   37 out of 39
Indefinite weights: 0 out of 39
Negative weights:   2 out of 39
Extension rule has valid weights: 0
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*** EXTENSION WITH INVALID WEIGHTS ***
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