Starting with polynomial:
P : t^7 - 21*t^5 + 105*t^3 - 105*t
Extension levels are: 7 12
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Trying to find an order 12 Kronrod extension for:
P1 : t^7 - 21*t^5 + 105*t^3 - 105*t
Solvable: 1
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Ending with final polynomial:
P : t^19 - 2216/17*t^17 + 225363/34*t^15 - 5780055/34*t^13 + 80911545/34*t^11 - 626247765/34*t^9 + 2593221345/34*t^7 - 5249048805/34*t^5 + 4234455225/34*t^3 - 46621575/2*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: 1
  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
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The nodes are:
| (2.9944098549047408593 - 2.090748433161360402e-288j)  +/-  (1.85e-123, 1.85e-123j)
| (-5.5561100339252269112 - 4.3214880262693475526e-292j)  +/-  (2.11e-123, 2.11e-123j)
| (-6.6975325765071699672 - 1.5168266396552284208e-294j)  +/-  (6.2e-124, 6.2e-124j)
| (-4.6012893561154538599 + 2.1144253856713552727e-302j)  +/-  (3.64e-123, 3.64e-123j)
| (6.6975325765071699672 + 1.3154003754877347992e-319j)  +/-  (6.07e-124, 6.07e-124j)
| (-1.7959546094993769997 - 4.0042183065315259643e-338j)  +/-  (1.76e-124, 1.76e-124j)
| (4.6012893561154538599 + 5.6330920651665602716e-355j)  +/-  (3.3e-123, 3.3e-123j)
| (-1.1544053947399681272 - 2.4813230159620680104e-364j)  +/-  (1.97e-125, 1.97e-125j)
| (1.1544053947399681272 - 4.5001673001544202198e-368j)  +/-  (1.97e-125, 1.97e-125j)
| (5.5561100339252269112 + 5.2609565511307966249e-371j)  +/-  (2e-123, 2e-123j)
| (0 - 5.0373886973319729887e-380j)  +/-  (9.57e-379, 9.57e-379j)
| (0.51169598081006329412 + 4.7391752864499201877e-376j)  +/-  (1.87e-126, 1.87e-126j)
| (-2.3667594107345412886 + 7.1638276330031555447e-373j)  +/-  (8.55e-124, 8.55e-124j)
| (-2.9944098549047408593 - 1.4749474105788016911e-376j)  +/-  (1.91e-123, 1.91e-123j)
| (3.7504397177257422563 - 3.9921305426355885935e-378j)  +/-  (3.27e-123, 3.27e-123j)
| (2.3667594107345412886 - 5.0442296335206714993e-385j)  +/-  (8.37e-124, 8.37e-124j)
| (1.7959546094993769997 + 3.4819235315556393028e-390j)  +/-  (1.89e-124, 1.89e-124j)
| (-3.7504397177257422563 + 1.5748831762792776452e-391j)  +/-  (3.17e-123, 3.17e-123j)
| (-0.51169598081006329412 - 4.019699158205720197e-396j)  +/-  (1.87e-126, 1.87e-126j)
-------------------------------------------------
The weights are:
| (0.0031451265939855343999 + 1.7695054840022987653e-290j)  +/-  (3.8e-46, 1.02e-107j)
| (8.0887172413281458375e-08 - 4.4502517710476801547e-295j)  +/-  (2.76e-51, 7.4e-113j)
| (9.4940453455990014675e-11 + 7.3346763395939626946e-297j)  +/-  (5.99e-53, 1.61e-114j)
| (9.0415880608410985259e-06 + 9.9719067201131793981e-294j)  +/-  (3.06e-50, 8.21e-112j)
| (9.4940453455990014675e-11 - 1.9198017707486053853e-296j)  +/-  (1.43e-54, 3.85e-116j)
| (0.048063556171494640814 + 1.3989196454762827351e-290j)  +/-  (2.8e-46, 7.51e-108j)
| (9.0415880608410985259e-06 - 4.7133564303924790117e-293j)  +/-  (3.66e-52, 9.83e-114j)
| (0.13573035088023066203 - 3.1224919669817411968e-290j)  +/-  (1.87e-45, 5.02e-107j)
| (0.13573035088023066203 - 7.0405061654932590217e-290j)  +/-  (2.65e-46, 7.13e-108j)
| (8.0887172413281458375e-08 + 1.4850220081987986551e-294j)  +/-  (2.12e-53, 5.69e-115j)
| (0.18035093636116654019 - 1.0610865134819866775e-289j)  +/-  (1.56e-45, 4.2e-107j)
| (0.20884223855008832032 + 9.8025939076424769183e-290j)  +/-  (1.12e-45, 3.02e-107j)
| (0.013750281835550528794 - 5.175834048992700191e-291j)  +/-  (5.97e-49, 1.61e-110j)
| (0.0031451265939855343999 + 1.0980143084151445856e-291j)  +/-  (2.6e-50, 7e-112j)
| (0.00028385521789333570391 + 1.1516451480330305781e-291j)  +/-  (1.71e-51, 4.59e-113j)
| (0.013750281835550528794 - 4.4209502853374236997e-290j)  +/-  (3.81e-50, 1.02e-111j)
| (0.048063556171494640814 + 5.5915868254746581694e-290j)  +/-  (1.11e-49, 2.97e-111j)
| (0.00028385521789333570391 - 1.290923754388851801e-292j)  +/-  (3.63e-52, 9.92e-114j)
| (0.20884223855008832032 + 6.9413477392443236736e-290j)  +/-  (4.1e-49, 1.04e-110j)
