Starting with polynomial:
P : 63/8*t^5 - 35/4*t^3 + 15/8*t
Extension levels are: 5 12 16
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Trying to find an order 12 Kronrod extension for:
P1 : 63/8*t^5 - 35/4*t^3 + 15/8*t
Solvable: 1
-------------------------------------------------
Trying to find an order 16 Kronrod extension for:
P2 : 63/8*t^17 - 15500107/453038*t^15 + 14463685/235828*t^13 - 754990808/12911583*t^11 + 2466422101/77469498*t^9 - 2971987447/301270270*t^7 + 61205289431/37615745140*t^5 - 683012759/5642361771*t^3 + 39745277/15046298056*t
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 63/8*t^33 - 357119827861575879523817160898812120678503011387011335775536542674041480747869/5539987253303448857924276248914531888437454548043129635050252507812502710254*t^31 + 5806663358553543098087313190683548922907314323485160516944874459869664302158652277/24209744296936071509129087207756504352471676374948476505169603459140636843809980*t^29 - 7057667150864891034870723711461362261619210793870404623941920825058165853728624253/13148395609542866423061487018005687708669962169153051895049008775222932078965765*t^27 + 370123674342800831865923446704514326743730338046831491489469340725202907964269982299893/459349580931703361805250202779569230908470920454758567731349002358814623967152394300*t^25 - 1414646881089669598912532727124993701830881032935101817800839378363151974779081906121383/1651538416365216548521338036762851219435533140158108881212557874634691963401900223814*t^23 + 156178682824909779073995967355000926887862397386931714887249783641945186100878570735438453671323/235341609396217446571422178120148090921799366211725265233727577252142099855828728884807294500*t^21 - 3189551999022054031404031309585233072372040682482941921030958898007464747486549607905581216192408/8396652420957901040173241283643855101102770244482626427446208916960355634141889291282945971625*t^19 + 30017753406959790986058254797891750597716966852413557317121436560604569271140916669403802267717877671/186312878639560078922454568040600677477574574072180551344581432489542964831467321384840904851441250*t^17 - 28126908534580575984734498528800115619852851870116870670248915322839685676838433811186615099686501327/558938635918680236767363704121802032432723722216541654033744297468628894494401964154522714554323750*t^15 + 849278846299325589620309833994728948796785863856161219975145135983570290905793590096395849435780053/74525151455824031568981827216240270991029829628872220537832572995817185932586928553936361940576500*t^13 - 75726086022747036374179786384564287656511331807392242783309815919440571481916905045956707626896641/41562103696517248375009095947518612668074328062255661453791242632282661385481171693541432620706125*t^11 + 885456612782467723464568411525306232503471144229658067265523228738042810703927389455208803727789403/4488707199223862824500982362332010168152027430723611437009454204286527429631966542902474723036261500*t^9 - 591450667592179640183727182774103932299825543297565234533899227318835156499951023180553698110404939/43640208881343110793759550744894543301478044465368444526480804763896794454755230278218504251741431250*t^7 + 152457455792233320183316749454122370469689688653384167886474446531835634541472503406922820698302273/286778515505969013787562762037878427409712863629564064031159574162750363559820084685435885082872262500*t^5 - 423165850918855996406547182609031086496725045812974801170232806538988776841319437676922072782342/43016777325895352068134414305681764111456929544434609604673936124412554533973012702815382762430839375*t^3 + 68477498187654801489678671327112551668314595682597515383298554420922655179035898381972306633/1236254519481205050927667039981778813564275532379289215335685061620478027824522202841357190374265000*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:
| (0.9962698516849579968 + 4.5963101733464650638e-310j)  +/-  (4.27e-117, 4.27e-117j)
| (2.3594936600537867744e-311 + 2.1436657129406003411e-311j)  +/-  (1.05e-309, 1.05e-309j)
| (-0.9061798459386639928 - 1.0086822157435235889e-314j)  +/-  (6.21e-117, 6.21e-117j)
| (-0.96827060709476223499 - 1.0472264373223359656e-328j)  +/-  (2.49e-116, 2.49e-116j)
| (0.94551687263152459739 + 9.9462517362781018871e-346j)  +/-  (1.53e-116, 1.53e-116j)
| (0.9061798459386639928 + 4.1559659094028884487e-344j)  +/-  (5.97e-117, 5.97e-117j)
| (-0.98189805109989378087 - 2.960939508652729418e-342j)  +/-  (1.94e-116, 1.94e-116j)
| (-0.85946974239072605693 - 3.4603793718209467264e-354j)  +/-  (2.77e-117, 2.77e-117j)
| (-0.9962698516849579968 - 5.8117356410978093387e-355j)  +/-  (4.46e-117, 4.46e-117j)
| (0.98189805109989378087 - 1.3717551247001959238e-362j)  +/-  (2.06e-116, 2.06e-116j)
| (0.85946974239072605693 + 3.2269764444721706346e-366j)  +/-  (2.83e-117, 2.83e-117j)
| (0.96827060709476223499 - 9.2082388138512211243e-367j)  +/-  (2.43e-116, 2.43e-116j)
| (-0.3701498540017078954 - 6.6596182396819480813e-373j)  +/-  (4.88e-123, 4.88e-123j)
| (-0.81141684513575577466 + 1.0123682867195938921e-367j)  +/-  (1.13e-117, 1.13e-117j)
| (-0.68735255126326749856 - 3.8460295221030204875e-370j)  +/-  (4.46e-119, 4.46e-119j)
| (0.81141684513575577466 + 7.1887869187599836674e-370j)  +/-  (1.03e-117, 1.03e-117j)
| (0.75569380316189441419 + 1.3044086891160766977e-371j)  +/-  (2.43e-118, 2.43e-118j)
| (-0.94551687263152459739 + 2.1507756680048012446e-372j)  +/-  (1.55e-116, 1.55e-116j)
| (-0.75569380316189441419 + 9.8817969474470288047e-386j)  +/-  (2.62e-118, 2.62e-118j)
| (-0.27815860931240380335 + 5.6938950508526246608e-392j)  +/-  (3.46e-124, 3.46e-124j)
| (0.53846931010568309104 - 6.6213631458996176348e-390j)  +/-  (7.75e-121, 7.75e-121j)
| (0.61304640697441226936 + 9.1178964356322168024e-388j)  +/-  (5.94e-120, 5.94e-120j)
| (0.27815860931240380335 - 3.6683465394181660067e-390j)  +/-  (3.13e-124, 3.13e-124j)
| (-0.53846931010568309104 - 6.6247646485335017526e-388j)  +/-  (7.8e-121, 7.8e-121j)
| (-0.45888640555451469594 - 8.5839297465750004716e-390j)  +/-  (8.32e-122, 8.32e-122j)
| (0.097048511523328935244 + 6.2481009274652568559e-391j)  +/-  (1.02e-126, 1.02e-126j)
| (0.68735255126326749856 - 2.7725908324703921028e-389j)  +/-  (4.79e-119, 4.79e-119j)
| (0.18847441760531908906 - 1.1023953301233057509e-392j)  +/-  (2e-125, 2e-125j)
| (-0.18847441760531908906 + 4.4160883215766746745e-394j)  +/-  (2e-125, 2e-125j)
| (-0.61304640697441226936 + 1.5647366800641831666e-390j)  +/-  (6.27e-120, 6.27e-120j)
| (-0.097048511523328935244 - 3.7551412917414299179e-396j)  +/-  (1.02e-126, 1.02e-126j)
| (0.3701498540017078954 + 8.4055565728306245973e-394j)  +/-  (4.97e-123, 4.97e-123j)
| (0.45888640555451469594 - 9.1959999134943095567e-392j)  +/-  (8.12e-122, 8.12e-122j)
-------------------------------------------------
The weights are:
| (0.0094652842925565971855 - 7.7981641470893767604e-310j)  +/-  (3.79e-19, 5.01e-75j)
| (0.09840079668658639806 - 1.511133279792724679e-310j)  +/-  (2.36e-19, 3.12e-75j)
| (0.044303062875774274847 - 3.0608771671221470229e-311j)  +/-  (6.38e-20, 8.44e-76j)
| (0.012638785842558810292 - 2.7656449761108257539e-311j)  +/-  (4.66e-20, 6.16e-76j)
| (0.033044531003052061106 + 1.0634025942986573134e-309j)  +/-  (1.24e-20, 1.63e-76j)
| (0.044303062875774274847 - 6.2699459388061041768e-310j)  +/-  (9.32e-21, 1.23e-76j)
| (0.017151000815025644917 + 1.455744664783762829e-311j)  +/-  (7.33e-21, 9.7e-77j)
| (0.047767691838611251396 + 4.3432068907107819968e-311j)  +/-  (9.56e-22, 1.26e-77j)
| (0.0094652842925565971855 - 2.2442171709227961659e-312j)  +/-  (2.1e-21, 2.78e-77j)
| (0.017151000815025644917 + 1.9487044953956774276e-309j)  +/-  (3.1e-22, 4.09e-78j)
| (0.047767691838611251396 + 5.7042117430125458224e-310j)  +/-  (1.29e-23, 1.71e-79j)
| (0.012638785842558810292 - 1.8865437951220879701e-309j)  +/-  (3.26e-22, 4.31e-78j)
| (0.091730032337959171566 - 1.0696913370586180277e-310j)  +/-  (1.5e-25, 1.98e-81j)
| (0.049791031616470364742 - 5.636299703936422991e-311j)  +/-  (2.12e-24, 2.8e-80j)
| (0.072725183604225670893 - 6.5145951090799710852e-311j)  +/-  (1.82e-25, 2.41e-81j)
| (0.049791031616470364742 - 5.3270903099430543964e-310j)  +/-  (5.22e-25, 6.9e-81j)
| (0.062615904449902705946 + 4.2500943800792531824e-310j)  +/-  (8.23e-26, 1.09e-81j)
| (0.033044531003052061106 + 2.8604873580372050116e-311j)  +/-  (1.8e-24, 2.38e-80j)
| (0.062615904449902705946 + 6.0532494265785849541e-311j)  +/-  (1.71e-25, 2.26e-81j)
| (0.091103651834309260159 + 1.2545592326198827727e-310j)  +/-  (7.39e-28, 9.77e-84j)
| (0.075524222479428585392 - 2.9842775167599848969e-310j)  +/-  (1.18e-28, 1.56e-84j)
| (0.074696746370028320036 + 3.1758458566957390022e-310j)  +/-  (2.6e-28, 3.44e-84j)
| (0.091103651834309260159 + 2.016454935257413617e-310j)  +/-  (9.1e-30, 1.2e-85j)
| (0.075524222479428585392 - 9.3692382809669996806e-311j)  +/-  (6.51e-29, 8.6e-85j)
| (0.084530302249126404995 + 9.99090263931491638e-311j)  +/-  (5.82e-29, 7.69e-85j)
| (0.094538573544467666708 + 1.5097957167001217335e-310j)  +/-  (1.29e-30, 1.7e-86j)
| (0.072725183604225670893 - 3.4108824036306004641e-310j)  +/-  (5.53e-30, 7.31e-86j)
| (0.089173596503210010791 - 1.8625944522667970261e-310j)  +/-  (7.11e-31, 9.4e-87j)
| (0.089173596503210010791 - 1.4701194156159957739e-310j)  +/-  (4.37e-31, 5.78e-87j)
| (0.074696746370028320036 + 7.9103401872920503573e-311j)  +/-  (9.48e-31, 1.25e-86j)
| (0.094538573544467666708 + 1.6522783430316214124e-310j)  +/-  (2.68e-31, 3.55e-87j)
| (0.091730032337959171566 - 2.1670051674413011971e-310j)  +/-  (1.86e-32, 2.47e-88j)
| (0.084530302249126404995 + 2.5477453940446466078e-310j)  +/-  (1.71e-32, 2.25e-88j)
