Starting with polynomial:
P : t^12 - 66*t^10 + 1485*t^8 - 13860*t^6 + 51975*t^4 - 62370*t^2 + 10395
Extension levels are: 12 25
-------------------------------------------------
Trying to find an order 25 Kronrod extension for:
P1 : t^12 - 66*t^10 + 1485*t^8 - 13860*t^6 + 51975*t^4 - 62370*t^2 + 10395
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : t^37 - 2242882561968/4258858723*t^35 + 8939123100043785/72400598291*t^33 - 1236158268592187160/72400598291*t^31 + 112633308964622075850/72400598291*t^29 - 50081627138100920708940/506804188037*t^27 + 29751136061177905715298870/6588454444481*t^25 - 994935787105269473595648000/6588454444481*t^23 + 3504700705746196080352899000/941207777783*t^21 - 63714067370241571654509847500/941207777783*t^19 + 848112169521766272861276643500/941207777783*t^17 - 479527219107833500642357143000/55365163399*t^15 + 3255793892271702277374179688750/55365163399*t^13 - 28362746464693530482639227500/103874603*t^11 + 3522730714418601001673686518750/4258858723*t^9 - 927140199102168631425567810000/608408389*t^7 + 929037777119335903616440531875/608408389*t^5 - 414606244223549817550807987500/608408389*t^3 + 52070220494912921376023128125/608408389*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
  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 37
Indefinite weights: 0 out of 37
Negative weights:   0 out of 37
Extension rule has valid weights: 1
-------------------------------------------------
The nodes are:
| (-5.1575314062638779202 - 8.4599137067942420807e-665j)  +/-  (6.81e-246, 6.81e-246j)
| (10.008925681707713538 + 1.0806884922849672308e-677j)  +/-  (1.16e-248, 1.16e-248j)
| (-9.0039569608663576455 - 4.0237576089946858141e-675j)  +/-  (9.61e-248, 9.61e-248j)
| (6.0885545646793584661 - 1.2096420608694944489e-678j)  +/-  (3.34e-246, 3.34e-246j)
| (8.1687671247127537235 + 2.7187882509697524261e-681j)  +/-  (4.39e-247, 4.39e-247j)
| (9.0039569608663576455 + 9.0355194795080265601e-684j)  +/-  (9.57e-248, 9.57e-248j)
| (-10.008925681707713538 + 1.7854037557741540181e-680j)  +/-  (1.02e-248, 1.02e-248j)
| (-2.7327245210473561455 - 1.6069571734427644513e-680j)  +/-  (5.55e-249, 5.55e-249j)
| (-3.7372296789015559107 + 7.3780663175200014494e-687j)  +/-  (1.42e-247, 1.42e-247j)
| (-6.7324359222288141449 - 1.9342404894151889535e-701j)  +/-  (2.24e-246, 2.24e-246j)
| (0.89023415981063470302 - 2.6740951760233515118e-712j)  +/-  (1.46e-252, 1.46e-252j)
| (1.3403751971516167215 - 4.8191005224775421785e-711j)  +/-  (1.64e-251, 1.64e-251j)
| (-0.89023415981063470302 + 2.0491488112509331273e-712j)  +/-  (1.46e-252, 1.46e-252j)
| (-3.2237098287700974717 - 9.1125308196232141516e-709j)  +/-  (3.27e-248, 3.27e-248j)
| (6.7324359222288141449 - 2.7540421803314510916e-705j)  +/-  (2.25e-246, 2.25e-246j)
| (3.2237098287700974717 + 1.2926900099790297314e-710j)  +/-  (3.12e-248, 3.12e-248j)
| (-2.2594644510007991239 - 1.5707778240150091372e-713j)  +/-  (9.31e-250, 9.31e-250j)
| (5.1575314062638779202 - 2.1399063399460476538e-707j)  +/-  (6.56e-246, 6.56e-246j)
| (-4.8092446722652021654 - 2.721411923884782158e-723j)  +/-  (3.25e-246, 3.25e-246j)
| (-8.1687671247127537235 + 5.703907620996787534e-741j)  +/-  (3.97e-247, 3.97e-247j)
| (-7.4216317009920332845 - 7.5185718286103375353e-759j)  +/-  (1.19e-246, 1.19e-246j)
| (1.7966066097362775546 - 3.3853237130858831589e-778j)  +/-  (1.4e-250, 1.4e-250j)
| (4.8092446722652021654 - 6.9985872999544815674e-776j)  +/-  (3.09e-246, 3.09e-246j)
| (-6.0885545646793584661 - 2.7248006293799749328e-796j)  +/-  (3.52e-246, 3.52e-246j)
| (7.4216317009920332845 + 3.3174038505415631294e-809j)  +/-  (1.19e-246, 1.19e-246j)
| (3.7372296789015559107 + 1.1668443490503815784e-817j)  +/-  (1.33e-247, 1.33e-247j)
| (-4.271825847932281723 + 1.2301230541591485137e-840j)  +/-  (5.57e-247, 5.57e-247j)
| (2.2594644510007991239 + 1.6497833739971207664e-861j)  +/-  (1.02e-249, 1.02e-249j)
| (-0.4444030019441389453 + 1.6180312607427928158e-868j)  +/-  (9.8e-254, 9.8e-254j)
| (-1.3403751971516167215 + 2.3935215956290653968e-860j)  +/-  (1.51e-251, 1.51e-251j)
| (-5.5009017044677476008 - 1.3257103098543810528e-863j)  +/-  (5.66e-246, 5.66e-246j)
| (4.271825847932281723 - 1.308144613896465849e-879j)  +/-  (5.84e-247, 5.84e-247j)
| (2.7327245210473561455 - 5.0738391289821508658e-891j)  +/-  (6.33e-249, 6.33e-249j)
| (5.5009017044677476008 - 3.2553995940575985213e-897j)  +/-  (6.29e-246, 6.29e-246j)
| (0.4444030019441389453 + 4.9485820592501698848e-917j)  +/-  (1.12e-253, 1.12e-253j)
| (-1.7966066097362775546 - 1.575816276785739936e-912j)  +/-  (1.26e-250, 1.26e-250j)
| (-8.4390273693384802048e-918 + 2.807026571680876594e-917j)  +/-  (1.08e-915, 1.08e-915j)
-------------------------------------------------
The weights are:
| (1.3147493565175151077e-07 - 3.685717427469909486e-671j)  +/-  (3.32e-87, 1.09e-209j)
| (8.15208047840793445e-23 + 2.9454531167934562257e-683j)  +/-  (6.48e-98, 2.13e-220j)
| (8.9064625831514595601e-19 + 2.507676314593226078e-680j)  +/-  (1.08e-96, 3.53e-219j)
| (2.2120196105677625166e-09 - 1.0540827383259842228e-674j)  +/-  (4.7e-91, 1.54e-213j)
| (1.0121158225901856298e-15 + 4.8946415960747415506e-679j)  +/-  (2.58e-95, 8.5e-218j)
| (8.9064625831514595601e-19 - 6.8111416039567523552e-681j)  +/-  (1.29e-96, 4.23e-219j)
| (8.15208047840793445e-23 - 9.2080927181284377784e-683j)  +/-  (6.73e-100, 2.21e-222j)
| (0.0045851082276283118485 + 6.2204939468003145206e-670j)  +/-  (4.68e-83, 1.54e-205j)
| (0.00019413835294084595168 + 1.3192232300075370244e-670j)  +/-  (4.4e-87, 1.45e-209j)
| (3.8169666253871912472e-11 - 3.7319605212284487741e-675j)  +/-  (5.47e-95, 1.8e-217j)
| (0.12011505174679715688 + 2.6995522683340444081e-669j)  +/-  (2.13e-77, 7e-200j)
| (0.073617271095376963155 - 1.7346891055316812345e-669j)  +/-  (1.7e-77, 5.59e-200j)
| (0.12011505174679715688 + 3.825901574074352308e-669j)  +/-  (4.3e-78, 1.41e-200j)
| (0.0011089072345245015556 - 2.9196560892858451997e-670j)  +/-  (1.78e-85, 5.85e-208j)
| (3.8169666253871912472e-11 + 4.9432276102251830981e-676j)  +/-  (3e-95, 9.88e-218j)
| (0.0011089072345245015556 - 6.7365844580626011397e-671j)  +/-  (1.98e-88, 6.52e-211j)
| (0.014509056157831977429 - 1.1890654670813407793e-669j)  +/-  (1.29e-83, 4.24e-206j)
| (1.3147493565175151077e-07 - 1.078293589127702259e-672j)  +/-  (5.22e-93, 1.72e-215j)
| (1.9356769101483087337e-06 + 6.9901092166496395238e-671j)  +/-  (3.22e-91, 1.06e-213j)
| (1.0121158225901856298e-15 - 2.1661358063662247599e-678j)  +/-  (1.07e-98, 3.52e-221j)
| (3.12313799794150777e-13 + 1.0470309359749262186e-676j)  +/-  (2.35e-97, 7.72e-220j)
| (0.036487130605430006827 + 9.6589464354178362292e-670j)  +/-  (7.07e-87, 2.32e-209j)
| (1.9356769101483087337e-06 + 2.4426778430440040256e-672j)  +/-  (1.85e-94, 6.08e-217j)
| (2.2120196105677625166e-09 + 1.2732556637893882181e-673j)  +/-  (1.54e-95, 5.07e-218j)
| (3.12313799794150777e-13 - 1.8845316103449912907e-677j)  +/-  (5.53e-99, 1.82e-221j)
| (0.00019413835294084595168 + 2.1065153008783467301e-671j)  +/-  (1.75e-93, 5.77e-216j)
| (2.3586010264810618117e-05 - 6.8171873570175857077e-671j)  +/-  (5.13e-93, 1.69e-215j)
| (0.014509056157831977429 - 4.64607423828928712e-670j)  +/-  (3.01e-91, 9.91e-214j)
| (0.16073690772201161621 - 4.3216520150402167228e-669j)  +/-  (1.36e-88, 4.49e-211j)
| (0.073617271095376963155 - 2.9529438084820228054e-669j)  +/-  (9.02e-90, 2.97e-212j)
| (5.6792201955397991221e-08 - 6.8975770393067880624e-672j)  +/-  (9.28e-95, 3.05e-217j)
| (2.3586010264810618117e-05 - 6.4034276902704409554e-672j)  +/-  (1.02e-94, 3.34e-217j)
| (0.0045851082276283118485 + 1.9116612554278625513e-670j)  +/-  (4.59e-93, 1.51e-215j)
| (5.6792201955397991221e-08 + 2.2221118810467701433e-673j)  +/-  (2.87e-96, 9.41e-219j)
| (0.16073690772201161621 - 3.6359763220054359346e-669j)  +/-  (6.2e-92, 2.03e-214j)
| (0.036487130605430006827 + 1.9985465509505155685e-669j)  +/-  (7.39e-93, 2.76e-215j)
| (0.17724143330528690089 + 4.2488962960111764269e-669j)  +/-  (3.9e-92, 1.16e-214j)
