Starting with polynomial:
P : 1/720*t^6 - 1/20*t^5 + 5/8*t^4 - 10/3*t^3 + 15/2*t^2 - 6*t + 1
Extension levels are: 6 11
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Trying to find an order 11 Kronrod extension for:
P1 : 1/720*t^6 - 1/20*t^5 + 5/8*t^4 - 10/3*t^3 + 15/2*t^2 - 6*t + 1
Solvable: 1
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Ending with final polynomial:
P : 1/720*t^17 - 260322918421133747/844950285602589600*t^16 + 353975289260728444493/11829303998436254400*t^15 - 265330933228311436835/157724053312483392*t^14 + 4809920475353750573485/78862026656241696*t^13 - 118652649960935508711155/78862026656241696*t^12 + 170699994176437952583631/6571835554686808*t^11 - 2090286059813803789411111/6571835554686808*t^10 + 9106779346366623864039955/3285917777343404*t^9 - 56165460606775250848984185/3285917777343404*t^8 + 60468125542062185548791630/821479444335851*t^7 - 25383698538024516677687898/117354206333693*t^6 + 49132387645944610136236668/117354206333693*t^5 - 59398105123945501050089700/117354206333693*t^4 + 41274177373030983131480400/117354206333693*t^3 - 14284310016781250519634000/117354206333693*t^2 + 1820432575969290394388640/117354206333693*t - 30709685533112203004640/117354206333693
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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
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The nodes are:
| (46.58771265138829793 + 4.8603448262054391938e-274j)  +/-  (5.29e-121, 5.29e-121j)
| (37.260660370011979771 - 4.7470879179350405848e-281j)  +/-  (2.84e-120, 2.84e-120j)
| (24.64898185839225624 + 1.0566773242943960278e-292j)  +/-  (1.67e-119, 1.67e-119j)
| (30.287531950315148412 + 2.9538045602505968849e-307j)  +/-  (8.26e-120, 8.26e-120j)
| (1.9322739096417129251 - 9.666371436238021603e-316j)  +/-  (8.26e-123, 8.26e-123j)
| (15.982873980601701783 + 1.26731728201511765e-324j)  +/-  (1.94e-119, 1.94e-119j)
| (5.7751435691045105018 + 5.2450803065735514976e-336j)  +/-  (1.22e-120, 1.22e-120j)
| (19.948743784782542962 + 1.808385090675767616e-343j)  +/-  (1.86e-119, 1.86e-119j)
| (0.019764465446277086064 + 1.7802082975818189198e-354j)  +/-  (5.97e-128, 5.97e-128j)
| (2.9927363260593140777 + 1.0468599192198132004e-350j)  +/-  (5.12e-122, 5.12e-122j)
| (1.1889321016726230307 - 1.5650291271803396254e-358j)  +/-  (1.04e-123, 1.04e-123j)
| (4.2963166355593006187 - 7.3357324086497515022e-362j)  +/-  (3.1e-121, 3.1e-121j)
| (9.8374674183825899177 - 4.2419810865633346631e-376j)  +/-  (6.94e-120, 6.94e-120j)
| (12.634206678955596588 - 3.4137912219258408805e-387j)  +/-  (1.27e-119, 1.27e-119j)
| (7.565010305913315465 + 1.3844532055879432316e-393j)  +/-  (3.32e-120, 3.32e-120j)
| (0.64545921449118526472 - 1.8924001473901427142e-401j)  +/-  (9.22e-125, 9.22e-125j)
| (0.22284660417926068946 + 7.818503591370152134e-403j)  +/-  (2.68e-126, 2.68e-126j)
-------------------------------------------------
The weights are:
| (6.6347802001890737487e-20 - 1.7638081923740733886e-293j)  +/-  (4.95e-52, 3.41e-111j)
| (5.1785331374061028737e-16 + 4.9943454242264114874e-292j)  +/-  (1.28e-50, 8.85e-110j)
| (1.0110495077068751335e-10 + 2.3810823282640772041e-289j)  +/-  (1.01e-48, 6.98e-108j)
| (4.361340629052470066e-13 - 1.3172196644763726736e-290j)  +/-  (9.14e-50, 6.31e-109j)
| (0.1308754518925856818 - 3.9176769036692999049e-283j)  +/-  (3.11e-37, 2.15e-96j)
| (4.1700943975874147462e-07 + 3.0626559201945593985e-287j)  +/-  (1.84e-47, 1.27e-106j)
| (0.0049511791616099613322 + 3.1045952370261629561e-284j)  +/-  (1.16e-43, 8.02e-103j)
| (9.3466431934865703736e-09 - 3.0882718719455413034e-288j)  +/-  (2.69e-48, 1.86e-107j)
| (0.077477433233598014907 - 1.7364070993734940072e-283j)  +/-  (9.14e-40, 6.31e-99j)
| (0.06023514677933878755 + 1.8829993260803146893e-283j)  +/-  (1.16e-41, 8.03e-101j)
| (0.18486497038345109794 + 6.1960582777672812645e-283j)  +/-  (4.03e-40, 2.78e-99j)
| (0.01892537092101021872 - 8.3262669434608971485e-284j)  +/-  (5.88e-43, 4.06e-102j)
| (0.00013525112759798940585 + 1.5956173191449388136e-285j)  +/-  (1.22e-46, 8.42e-106j)
| (9.9889611311489124445e-06 - 2.4374012565501509718e-286j)  +/-  (1.52e-47, 1.05e-106j)
| (0.001045057855897710732 - 8.3227575618088278884e-285j)  +/-  (7.34e-46, 5.07e-105j)
| (0.26037810055255333513 - 6.4023599487301699142e-283j)  +/-  (9.54e-44, 6.6e-103j)
| (0.26110162267360149859 + 4.5689846852004039115e-283j)  +/-  (8.1e-44, 5.49e-103j)
