Starting with polynomial:
P : 67108864*t^26 - 10905190400*t^24 + 752458137600*t^22 - 28969638297600*t^20 + 688028909568000*t^18 - 10526842316390400*t^16 + 105268423163904000*t^14 - 684244750565376000*t^12 + 2822509596082176000*t^10 - 7056273990205440000*t^8 + 9878783586287616000*t^6 - 6735534263377920000*t^4 + 1683883565844480000*t^2 - 64764752532480000
Extension levels are: 26 41
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Trying to find an order 41 Kronrod extension for:
P1 : 67108864*t^26 - 10905190400*t^24 + 752458137600*t^22 - 28969638297600*t^20 + 688028909568000*t^18 - 10526842316390400*t^16 + 105268423163904000*t^14 - 684244750565376000*t^12 + 2822509596082176000*t^10 - 7056273990205440000*t^8 + 9878783586287616000*t^6 - 6735534263377920000*t^4 + 1683883565844480000*t^2 - 64764752532480000
Solvable: 1
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Ending with final polynomial:
P : 67108864*t^67 - 18476417561722653006300122550835143914483230928291166101469921280/347370223533358277498175832229340565547938809983077593*t^65 + 6859507468362932600585381700619019259375273462534281425160587182080/347370223533358277498175832229340565547938809983077593*t^63 - 176394677421965834921341485504790895778862668420192557793229165035520/38596691503706475277575092469926729505326534442564177*t^61 + 85722099753986342251202480729002108480605705535820270043629943468851200/115790074511119425832725277409780188515979603327692531*t^59 - 10345185512861692754232767809483393773726510676317581604312547351278387200/115790074511119425832725277409780188515979603327692531*t^57 + 322228804721976990925463196002944160895126521735430696577866258692282777600/38596691503706475277575092469926729505326534442564177*t^55 - 7973820071377667400051915041362967676152262219984164604861002861511180288000/12865563834568825092525030823308909835108844814188059*t^53 + 478825520891858610109835866824542204665657267148614160417523307067388198912000/12865563834568825092525030823308909835108844814188059*t^51 - 23560179839658498076175655298997788291661297352677244780586238289790272405504000/12865563834568825092525030823308909835108844814188059*t^49 + 958791277005067134221517759185149413334935886352197784601411337288790117528371200/12865563834568825092525030823308909835108844814188059*t^47 - 32487705809863537555916106782503958996904349610793008280064129695058985406038016000/12865563834568825092525030823308909835108844814188059*t^45 + 920819684842141998015355295857324431084696789128861230059487534080969464941092864000/12865563834568825092525030823308909835108844814188059*t^43 - 21896391105342601214833920204174808713085565761372400028396983680089557860148465664000/12865563834568825092525030823308909835108844814188059*t^41 + 437494645536770156010377044417098557491531387799608273375988930931064918122734407680000/12865563834568825092525030823308909835108844814188059*t^39 - 7346502881383476875533389941567229896081452724469480197571853733285071705739026593792000/12865563834568825092525030823308909835108844814188059*t^37 + 103582274030262304445353768456969997014621349190624789503118400755283879869038850881280000/12865563834568825092525030823308909835108844814188059*t^35 - 1223698316835224358581195180278863149815468640330526427741349807789944445578687835982720000/12865563834568825092525030823308909835108844814188059*t^33 + 12073302000514303930408873365028146524341265717894250847073608770613309571569311948702720000/12865563834568825092525030823308909835108844814188059*t^31 - 99033716352416211340490526585820211633695395827516377219448911142408004783946603071609600000/12865563834568825092525030823308909835108844814188059*t^29 + 671431319650044254347927364616495451510955166365375620816037571864597468885451949543883360000/12865563834568825092525030823308909835108844814188059*t^27 - 3734858712103058663870392011252803597070276474939269001444947586318286399521177886068270000000/12865563834568825092525030823308909835108844814188059*t^25 + 16889537266986187994836552272784064805920073235018478814407897932557827225013807391928274000000/12865563834568825092525030823308909835108844814188059*t^23 - 61392392094874664419463763304311313547336559760280585008355018785269201616370387573489799000000/12865563834568825092525030823308909835108844814188059*t^21 + 176882959299720794270256404195801080075110717306784216222111235627436182317978367322511635000000/12865563834568825092525030823308909835108844814188059*t^19 - 396978130687114472479648735239863903873550002103505559991336704949825292419578338027118671500000/12865563834568825092525030823308909835108844814188059*t^17 + 678926403410531940237153644047194727796097567339265523943253327053686766197725834589941443750000/12865563834568825092525030823308909835108844814188059*t^15 - 860241794099574177677928429272273584890036970074071809039017763486321775622773553723657997500000/12865563834568825092525030823308909835108844814188059*t^13 + 778164573536132374552512141843412059453748609660171541604783568389761230331133696035041111171875/12865563834568825092525030823308909835108844814188059*t^11 - 955764581167530899554475954406683299986569964353773416071215848068190238006813736361116073046875/25731127669137650185050061646617819670217689628376118*t^9 + 370965678493116523469322700326059937826511636239037631888187996157097874715722830116591613984375/25731127669137650185050061646617819670217689628376118*t^7 - 163085286946746061196322263801433987443630793950360988859889800231135965963099669580679333203125/51462255338275300370100123293235639340435379256752236*t^5 + 266855148052301404998026147698827551689093317914562088399632586549891165138766978628262196484375/823396085412404805921601972691770229446966068108035776*t^3 - 15665842203543451257435272427605365494450235123019359800244599736175521790675037906326058984375/1646792170824809611843203945383540458893932136216071552*t
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Computing nodes and weights
  current precision for roots: 53
  current precision for roots: 106
  current precision for roots: 212
 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: 0
  current precision for roots: 424
  current precision for roots: 848
 current precision for weights: 424
Linear system for weights solvable: 1
  current precision for roots: 848
  current precision for roots: 1696
 current precision for weights: 848
Linear system for weights solvable: 1
Sufficient bits for target precision reached
Positive weights:   65 out of 67
Indefinite weights: 0 out of 67
Negative weights:   2 out of 67
Extension rule has valid weights: 0
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*** EXTENSION WITH INVALID WEIGHTS ***
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