Starting with polynomial:
P : 4096*t^12 - 135168*t^10 + 1520640*t^8 - 7096320*t^6 + 13305600*t^4 - 7983360*t^2 + 665280
Extension levels are: 12 25
-------------------------------------------------
Trying to find an order 25 Kronrod extension for:
P1 : 4096*t^12 - 135168*t^10 + 1520640*t^8 - 7096320*t^6 + 13305600*t^4 - 7983360*t^2 + 665280
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 4096*t^37 - 4593423486910464/4258858723*t^35 + 9153662054444835840/72400598291*t^33 - 632913033519199825920/72400598291*t^31 + 28834127094943251417600/72400598291*t^29 - 6410448273676917850744320/506804188037*t^27 + 1904072707915385965779127680/6588454444481*t^25 - 31837945187368623155060736000/6588454444481*t^23 + 56075211291939137285646384000/941207777783*t^21 - 509712538961932573236078780000/941207777783*t^19 + 3392448678087065091445106574000/941207777783*t^17 - 959054438215667001284714286000/55365163399*t^15 + 3255793892271702277374179688750/55365163399*t^13 - 14181373232346765241319613750/103874603*t^11 + 1761365357209300500836843259375/8517717446*t^9 - 115892524887771078928195976250/608408389*t^7 + 929037777119335903616440531875/9734534224*t^5 - 103651561055887454387701996875/4867267112*t^3 + 52070220494912921376023128125/38938136896*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
-------------------------------------------------
The nodes are:
| (-6.3667590245404190068 - 2.0580957558451557322e-745j)  +/-  (6.67e-248, 6.67e-248j)
| (4.3653183892983967735e-762 + 1.5901202161033648479e-762j)  +/-  (1.72e-760, 1.72e-760j)
| (6.3667590245404190068 + 8.4313962829892299483e-748j)  +/-  (6.99e-248, 6.99e-248j)
| (7.0773792219277122106 + 7.7450135257145487684e-748j)  +/-  (7.41e-249, 7.41e-249j)
| (5.7761906278181241196 + 3.2320809630793435741e-746j)  +/-  (3.08e-247, 3.08e-247j)
| (-7.0773792219277122106 + 7.3859510248411161814e-747j)  +/-  (7.79e-249, 7.79e-249j)
| (-5.7761906278181241196 - 4.2089283323233571868e-744j)  +/-  (3.02e-247, 3.02e-247j)
| (-5.2478861032405181833 - 2.0049525227610426999e-748j)  +/-  (7.57e-247, 7.57e-247j)
| (-1.5976826351526047967 - 1.449115326665545328e-758j)  +/-  (7.23e-250, 7.23e-250j)
| (3.6469254315517786686 - 1.9058397944959248726e-753j)  +/-  (4.44e-246, 4.44e-246j)
| (5.2478861032405181833 - 4.0006397754483363657e-759j)  +/-  (7.85e-247, 7.85e-247j)
| (2.6426204488029137606 - 1.0485064462067477412e-758j)  +/-  (1.01e-247, 1.01e-247j)
| (-2.2795070805010599002 + 8.9285566616930572759e-757j)  +/-  (2.16e-248, 2.16e-248j)
| (-2.6426204488029137606 - 2.6693387210740361805e-756j)  +/-  (9.51e-248, 9.51e-248j)
| (1.9323280399473457468 - 9.0661896344510465002e-765j)  +/-  (4.03e-249, 4.03e-249j)
| (3.8897248978697819193 + 2.5793995425270022169e-760j)  +/-  (4.27e-246, 4.27e-246j)
| (3.4006495201439997693 + 7.5037161646818206759e-762j)  +/-  (1.93e-246, 1.93e-246j)
| (4.76055109451190237 + 1.3858696251704732094e-764j)  +/-  (1.54e-246, 1.54e-246j)
| (-1.2703927168690949959 - 2.0311702728905512154e-769j)  +/-  (9.73e-251, 9.73e-251j)
| (4.3052582203090822433 - 3.9930444504105021081e-764j)  +/-  (2.72e-246, 2.72e-246j)
| (-1.9323280399473457468 + 4.8708550098807280054e-766j)  +/-  (4.05e-249, 4.05e-249j)
| (1.5976826351526047967 - 1.6229435879962407144e-770j)  +/-  (7.54e-250, 7.54e-250j)
| (-4.3052582203090822433 + 1.2970882791881640609e-772j)  +/-  (2.51e-246, 2.51e-246j)
| (-3.4006495201439997693 + 4.0246670536132696417e-801j)  +/-  (2.18e-246, 2.18e-246j)
| (-0.31424037625435911128 - 5.0039842659176392458e-831j)  +/-  (6.77e-254, 6.77e-254j)
| (1.2703927168690949959 + 6.2153235910871344157e-828j)  +/-  (1.07e-250, 1.07e-250j)
| (-3.8897248978697819193 + 4.2909519679152436153e-827j)  +/-  (4.3e-246, 4.3e-246j)
| (3.0206370251208897717 + 2.0658695654936816014e-845j)  +/-  (4.36e-247, 4.36e-247j)
| (-0.9477883912401637437 - 2.183684374613336936e-850j)  +/-  (1.14e-251, 1.14e-251j)
| (-0.62949061124600845307 - 5.1191222522001718585e-851j)  +/-  (9.99e-253, 9.99e-253j)
| (-3.0206370251208897717 - 1.4720220578591690154e-843j)  +/-  (4.62e-247, 4.62e-247j)
| (0.9477883912401637437 + 2.6171649396627757775e-861j)  +/-  (1.09e-251, 1.09e-251j)
| (0.31424037625435911128 - 1.3491982277202752289e-864j)  +/-  (7.15e-254, 7.15e-254j)
| (-3.6469254315517786686 + 1.3014485847818030823e-857j)  +/-  (4.37e-246, 4.37e-246j)
| (-4.76055109451190237 + 2.4705043871433909734e-870j)  +/-  (1.5e-246, 1.5e-246j)
| (0.62949061124600845307 - 1.0097613442102331724e-878j)  +/-  (1.09e-252, 1.09e-252j)
| (2.2795070805010599002 - 8.0154928076912303428e-876j)  +/-  (2.15e-248, 2.15e-248j)
-------------------------------------------------
The weights are:
| (8.9064625831514595601e-19 - 1.0797290768295703921e-760j)  +/-  (1.52e-91, 8.04e-216j)
| (0.17724143330528690089 - 2.4890469456663275635e-750j)  +/-  (1.27e-77, 6.73e-202j)
| (8.9064625831514595601e-19 + 4.346420051127944864e-762j)  +/-  (7.41e-92, 3.93e-216j)
| (8.15208047840793445e-23 - 2.0908656791026410104e-764j)  +/-  (9.14e-94, 4.84e-218j)
| (1.0121158225901856298e-15 - 5.9798205632094766097e-760j)  +/-  (1.1e-90, 5.82e-215j)
| (8.15208047840793445e-23 + 2.2278801184536381502e-763j)  +/-  (4.89e-95, 2.59e-219j)
| (1.0121158225901856298e-15 - 3.0001177430543902616e-758j)  +/-  (3.27e-92, 1.73e-216j)
| (3.12313799794150777e-13 + 2.9233269404700639782e-757j)  +/-  (2.64e-91, 1.4e-215j)
| (0.014509056157831977429 + 5.3931443854849201255e-751j)  +/-  (1.27e-77, 6.73e-202j)
| (1.3147493565175151077e-07 + 7.9460286643951802844e-754j)  +/-  (2.83e-88, 1.5e-212j)
| (3.12313799794150777e-13 + 1.6247738497055311656e-758j)  +/-  (3.44e-92, 1.82e-216j)
| (0.00019413835294084595168 - 1.4788821244754065244e-752j)  +/-  (3.42e-85, 1.81e-209j)
| (0.0011089072345245015556 + 1.0549209787683729217e-751j)  +/-  (5.34e-84, 2.83e-208j)
| (0.00019413835294084595168 - 3.9047669422262087047e-752j)  +/-  (8.98e-86, 4.76e-210j)
| (0.0045851082276283118485 - 1.2935589694635519227e-751j)  +/-  (3.1e-83, 1.64e-207j)
| (5.6792201955397991221e-08 - 1.6580616495823392458e-754j)  +/-  (1.17e-89, 6.2e-214j)
| (1.9356769101483087337e-06 - 1.7784560108003608936e-753j)  +/-  (1.5e-88, 7.95e-213j)
| (3.8169666253871912472e-11 - 3.921321457614716971e-757j)  +/-  (1.06e-92, 5.62e-217j)
| (0.036487130605430006827 - 9.7540382209571414235e-751j)  +/-  (1.12e-83, 5.93e-208j)
| (2.2120196105677625166e-09 + 8.0586746526972641003e-756j)  +/-  (1.88e-91, 9.98e-216j)
| (0.0045851082276283118485 - 2.5648753793488529512e-751j)  +/-  (5.88e-87, 3.12e-211j)
| (0.014509056157831977429 + 3.0837842518303791275e-751j)  +/-  (4.29e-86, 2.28e-210j)
| (2.2120196105677625166e-09 + 5.2548915580775929689e-755j)  +/-  (5.19e-96, 2.75e-220j)
| (1.9356769101483087337e-06 - 6.6873333493133780335e-753j)  +/-  (5.74e-94, 3.04e-218j)
| (0.16073690772201161621 + 2.4447283649204214763e-750j)  +/-  (4.67e-87, 2.48e-211j)
| (0.036487130605430006827 - 6.2805940208732771716e-751j)  +/-  (3.91e-88, 2.07e-212j)
| (5.6792201955397991221e-08 - 8.1888764250122498387e-754j)  +/-  (1.77e-95, 9.4e-220j)
| (2.3586010264810618117e-05 + 4.5782975031393527956e-753j)  +/-  (2.03e-92, 1.08e-216j)
| (0.073617271095376963155 + 1.5283724719130691519e-750j)  +/-  (6.54e-89, 3.47e-213j)
| (0.12011505174679715688 - 2.0781302459270687396e-750j)  +/-  (5.55e-89, 2.94e-213j)
| (2.3586010264810618117e-05 + 1.4303474219513432598e-752j)  +/-  (1.33e-93, 7.08e-218j)
| (0.073617271095376963155 + 1.1030942794004824197e-750j)  +/-  (9.51e-91, 5.04e-215j)
| (0.16073690772201161621 + 2.1960613028006106208e-750j)  +/-  (3.65e-90, 1.94e-214j)
| (1.3147493565175151077e-07 + 3.4078399721815518804e-753j)  +/-  (5.67e-95, 3e-219j)
| (3.8169666253871912472e-11 - 3.7720514586964501225e-756j)  +/-  (2.05e-98, 1.09e-222j)
| (0.12011505174679715688 - 1.6752499687710470342e-750j)  +/-  (1e-91, 5.43e-216j)
| (0.0011089072345245015556 + 4.6438476774612828705e-752j)  +/-  (1.5e-93, 7.85e-218j)
