Starting with polynomial:
P : 65536*t^16 - 3932160*t^14 + 89456640*t^12 - 984023040*t^10 + 5535129600*t^8 - 15498362880*t^6 + 19372953600*t^4 - 8302694400*t^2 + 518918400
Extension levels are: 16 23
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Trying to find an order 23 Kronrod extension for:
P1 : 65536*t^16 - 3932160*t^14 + 89456640*t^12 - 984023040*t^10 + 5535129600*t^8 - 15498362880*t^6 + 19372953600*t^4 - 8302694400*t^2 + 518918400
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 65536*t^39 - 8688664244074741760/517583353637*t^37 + 990262000761694863360/517583353637*t^35 - 9508323843336329256960/73940479091*t^33 + 421201458824633375539200/73940479091*t^31 - 13020231660780715306721280/73940479091*t^29 + 290117549060584583592038400/73940479091*t^27 - 4746980766094138315089561600/73940479091*t^25 + 57579864600285727289739072000/73940479091*t^23 - 519160629521416220138132640000/73940479091*t^21 + 3468607205454914311052787600000/73940479091*t^19 - 17022618682210577742963730920000/73940479091*t^17 + 60455882488038275870457071400000/73940479091*t^15 - 151935116226911540588791826100000/73940479091*t^13 + 261511778903513393054465716050000/73940479091*t^11 - 293592758641547278809747536685000/73940479091*t^9 + 198930385082023356722484470821875/73940479091*t^7 - 142422541931580126074411975296875/147880958182*t^5 + 42617326845917264694121427934375/295761916364*t^3 - 3785124500229339318122368171875/591523832728*t
-------------------------------------------------
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
Sufficient bits for target precision reached
-------------------------------------------------
The nodes are:
| (7.0157789415586014933 + 3.6342930569560889836e-465j)  +/-  (2.6e-121, 2.6e-121j)
| (4.6887389393058183647 - 1.9123939630068207599e-461j)  +/-  (5.28e-119, 5.28e-119j)
| (-5.7049691354401656094 + 1.6324542676675037117e-462j)  +/-  (1.11e-119, 1.11e-119j)
| (6.2998411262400427815 - 2.5807407671483706222e-463j)  +/-  (2.47e-120, 2.47e-120j)
| (-3.8694479048601226987 - 6.2299321017290828627e-462j)  +/-  (9.14e-119, 9.14e-119j)
| (-3.5386980464374883902 - 9.7169601461595720767e-464j)  +/-  (7.51e-119, 7.51e-119j)
| (-4.6887389393058183647 - 1.9404481433987695786e-471j)  +/-  (5.21e-119, 5.21e-119j)
| (-5.1741213525178433035 + 3.2770925996580715955e-474j)  +/-  (2.76e-119, 2.76e-119j)
| (5.1741213525178433035 - 2.5739757995150662765e-474j)  +/-  (2.83e-119, 2.83e-119j)
| (3.8694479048601226987 - 5.4127411658784674384e-473j)  +/-  (9.36e-119, 9.36e-119j)
| (2.7881670354390858566 - 7.4061412669652073769e-477j)  +/-  (2.92e-119, 2.92e-119j)
| (-1.9517879909162539774 - 1.1617114055080819689e-480j)  +/-  (6.32e-121, 6.32e-121j)
| (4.2479600889022859713 + 5.1904975209544291101e-477j)  +/-  (9e-119, 9e-119j)
| (-6.2998411262400427815 + 1.8422116065081081875e-481j)  +/-  (2.79e-120, 2.79e-120j)
| (3.5386980464374883902 - 9.314015247312219696e-477j)  +/-  (7.7e-119, 7.7e-119j)
| (1.9517879909162539774 - 2.4407892613705242474e-479j)  +/-  (5.62e-121, 5.62e-121j)
| (2.5462021578474813622 - 3.9844923035451436365e-478j)  +/-  (2.07e-119, 2.07e-119j)
| (-2.7881670354390858566 + 3.6437902297430122003e-481j)  +/-  (2.87e-119, 2.87e-119j)
| (-2.3524922557758196513 - 1.8303015137151244206e-482j)  +/-  (7.81e-120, 7.81e-120j)
| (-3.1769991619799560268 + 1.8425944522335462668e-492j)  +/-  (4.25e-119, 4.25e-119j)
| (1.3199022541923225136 - 3.7062942026488260336e-504j)  +/-  (1.88e-121, 1.88e-121j)
| (5.7049691354401656094 + 4.8160265112775589274e-502j)  +/-  (1.1e-119, 1.1e-119j)
| (2.3524922557758196513 + 1.4801677218132967711e-500j)  +/-  (7.35e-120, 7.35e-120j)
| (0.45129412234103662844 + 1.2144134616400510393e-509j)  +/-  (1.39e-125, 1.39e-125j)
| (-1.3199022541923225136 - 1.0809596106271767794e-505j)  +/-  (2e-121, 2e-121j)
| (1.3802585391988807964 + 9.9967764319896112937e-506j)  +/-  (5.11e-121, 5.11e-121j)
| (1.4492277782266551972 - 6.1531071029705078072e-506j)  +/-  (4.05e-121, 4.05e-121j)
| (-1.0358371248033725435e-513 - 1.8492001079349468559e-512j)  +/-  (7.22e-511, 7.22e-511j)
| (-1.4492277782266551972 - 4.7440349594602094282e-504j)  +/-  (3.91e-121, 3.91e-121j)
| (-1.3802585391988807964 - 8.4748650577844992101e-505j)  +/-  (5.16e-121, 5.16e-121j)
| (-2.5462021578474813622 - 1.4245430899815596972e-506j)  +/-  (2.09e-119, 2.09e-119j)
| (3.1769991619799560268 + 9.6073991410241144643e-515j)  +/-  (4.69e-119, 4.69e-119j)
| (0.82295144914465589258 + 9.2466804915335805202e-522j)  +/-  (2.72e-124, 2.72e-124j)
| (-0.82295144914465589258 + 7.2855895079929836224e-520j)  +/-  (2.6e-124, 2.6e-124j)
| (-0.45129412234103662844 - 1.6873508917491578073e-521j)  +/-  (1.51e-125, 1.51e-125j)
| (-7.0157789415586014933 + 4.3221159001802689103e-520j)  +/-  (2.72e-121, 2.72e-121j)
| (-0.27348104613815245216 + 1.8268429952404730017e-527j)  +/-  (2.77e-126, 2.77e-126j)
| (0.27348104613815245216 - 3.4395398023596219904e-528j)  +/-  (2.77e-126, 2.77e-126j)
| (-4.2479600889022859713 + 5.0302807822226418609e-524j)  +/-  (7.65e-119, 7.65e-119j)
-------------------------------------------------
The weights are:
| (1.956251481219858178e-22 - 2.0467568064235028431e-479j)  +/-  (5.53e-33, 1.38e-92j)
| (7.4252360808492088198e-11 + 1.0005192259249435929e-470j)  +/-  (8.62e-27, 2.15e-86j)
| (2.3078811048743511789e-15 + 5.9470113013518236658e-475j)  +/-  (3.87e-31, 9.64e-91j)
| (2.0946636917631573257e-18 + 7.9804845951391581887e-477j)  +/-  (2.01e-31, 5.01e-91j)
| (6.0830682400886961448e-08 - 2.5313577903318709645e-468j)  +/-  (2.08e-25, 5.18e-85j)
| (6.9394321764125698016e-07 + 7.6033419752186537927e-468j)  +/-  (2.78e-24, 6.94e-84j)
| (7.4252360808492088198e-11 + 1.6950523992681293637e-471j)  +/-  (8.99e-29, 2.24e-88j)
| (6.7505966146377972348e-13 - 3.5931948048576243788e-473j)  +/-  (2.71e-30, 6.77e-90j)
| (6.7505966146377972348e-13 + 9.8437787577546059414e-473j)  +/-  (1.3e-31, 3.25e-91j)
| (6.0830682400886961448e-08 + 4.6454459717566989708e-469j)  +/-  (1.36e-28, 3.39e-88j)
| (9.1149570763336520248e-05 - 9.469114012285455718e-467j)  +/-  (1.03e-25, 2.57e-85j)
| (0.0051793324840222993134 - 1.1636027796689191042e-465j)  +/-  (1.81e-22, 4.52e-82j)
| (3.3982370564314561994e-09 - 6.8340991260757438205e-470j)  +/-  (9.35e-30, 2.33e-89j)
| (2.0946636917631573257e-18 - 5.056779322239915088e-477j)  +/-  (3.44e-37, 8.59e-97j)
| (6.9394321764125698016e-07 - 2.2939907649726216593e-468j)  +/-  (3.78e-28, 9.42e-88j)
| (0.0051793324840222993134 + 8.1783214225713025263e-466j)  +/-  (4.85e-24, 1.21e-83j)
| (5.7255789326214789798e-05 + 3.5964779421167740523e-466j)  +/-  (9.99e-26, 2.49e-85j)
| (9.1149570763336520248e-05 + 1.6106547261369002565e-466j)  +/-  (1.78e-28, 4.45e-88j)
| (0.00083791148335366884001 + 7.7333942171118392249e-466j)  +/-  (2.64e-27, 6.59e-87j)
| (8.9229825069056125418e-06 - 2.3780847716777485446e-467j)  +/-  (1.59e-29, 3.97e-89j)
| (0.24564887928048390418 - 4.813978391655632513e-464j)  +/-  (4.92e-24, 1.23e-83j)
| (2.3078811048743511789e-15 - 1.0543751890836424609e-474j)  +/-  (9.85e-37, 2.46e-96j)
| (0.00083791148335366884001 - 5.1193571770896412153e-466j)  +/-  (4.54e-27, 1.13e-86j)
| (0.14407609986030057247 - 6.460080840511723506e-465j)  +/-  (7.97e-25, 1.99e-84j)
| (0.24564887928048390418 + 6.6652849376453989362e-464j)  +/-  (5.28e-26, 1.32e-85j)
| (-0.33468184900578713506 + 8.0225295909654734958e-464j)  +/-  (7.33e-25, 1.83e-84j)
| (0.15309272836567013638 - 3.4753687714661673609e-464j)  +/-  (2.57e-25, 6.41e-85j)
| (0.19660414709897331091 + 3.4740510493461807525e-465j)  +/-  (1.13e-25, 2.83e-85j)
| (0.15309272836567013638 + 4.8047573841649253166e-464j)  +/-  (5.23e-27, 1.31e-86j)
| (-0.33468184900578713506 - 1.1094116920609699554e-463j)  +/-  (1.39e-26, 3.45e-86j)
| (5.7255789326214789798e-05 - 5.6768135956735890121e-466j)  +/-  (2.97e-30, 7.47e-90j)
| (8.9229825069056125418e-06 + 1.145601991100366458e-467j)  +/-  (8.77e-32, 2.2e-91j)
| (0.11488171697337078897 + 4.3906402818203130315e-465j)  +/-  (1.41e-27, 3.61e-87j)
| (0.11488171697337078897 - 6.4883720503735912426e-465j)  +/-  (1.36e-28, 3.48e-88j)
| (0.14407609986030057247 + 1.2069828400938281544e-464j)  +/-  (1.61e-28, 4.16e-88j)
| (1.956251481219858178e-22 + 1.4570317296602037148e-479j)  +/-  (2.06e-45, 4.86e-105j)
| (0.072505020419435823504 - 1.2117811479433552998e-464j)  +/-  (1.31e-28, 3.49e-88j)
| (0.072505020419435823504 + 4.275909500181529162e-465j)  +/-  (7.89e-29, 2.26e-88j)
| (3.3982370564314561994e-09 - 7.8117649801918996877e-470j)  +/-  (1.96e-36, 4.43e-96j)
