Starting with polynomial:
P : 2268783825/65536*t^18 - 9917826435/65536*t^16 + 4508102925/16384*t^14 - 4411154475/16384*t^12 + 5019589575/32768*t^10 - 1673196525/32768*t^8 + 156165009/16384*t^6 - 14549535/16384*t^4 + 2078505/65536*t^2 - 12155/65536
Extension levels are: 18 20
-------------------------------------------------
Trying to find an order 20 Kronrod extension for:
P1 : 2268783825/65536*t^18 - 9917826435/65536*t^16 + 4508102925/16384*t^14 - 4411154475/16384*t^12 + 5019589575/32768*t^10 - 1673196525/32768*t^8 + 156165009/16384*t^6 - 14549535/16384*t^4 + 2078505/65536*t^2 - 12155/65536
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 2268783825/65536*t^38 - 272621385905/851968*t^36 + 1851310344692725/1362296832*t^34 - 8029678148247511525/2284571787264*t^32 + 5649602524679265100025/913257571958784*t^30 - 13129216950455215903094725/1674001129400451072*t^28 + 851142879683671291770421770479/115099295654186814357504*t^26 - 402782543171944966331236859272525/76310833018725857919025152*t^24 + 260380430575859786671071697168928218025/90539598321731443934890743791616*t^22 - 25972575433171780709165945538431107441775/21690700912220518782687396762648576*t^20 + 617656014504874466181829592245536301593933725/1630121245656108648075305928903328432128*t^18 - 959138205296233439106982655034869922113065/10654387226510514039707881888257048576*t^16 + 11076296042599795051109807605058733496475/703591609297864134697690313375465472*t^14 - 2417372297517211459610495178927960743675/1229352372289674696889370987106582528*t^12 + 68767416862321403293857521960142361975/409784124096558232296456995702194176*t^10 - 8745885630637310210411089014606537575/956162956225302542025066323305119744*t^8 + 4213846106672615016617542700997154505/14752228467476096362672451845278990336*t^6 - 20646121895650116197476164995001775/4917409489158698787557483948426330112*t^4 + 272040590670456351810196449973775/14752228467476096362672451845278990336*t^2 - 81199635657983392050807454775/309796797816998023616121488750858797056
-------------------------------------------------
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:
| (-0.99156516842093094673 + 7.7917802649537673182e-420j)  +/-  (4.97e-115, 4.97e-115j)
| (0.80370495897252311568 - 2.0043939683262129079e-427j)  +/-  (1.44e-116, 1.44e-116j)
| (-0.89260246649755573921 - 1.9798892391450163546e-423j)  +/-  (1.23e-115, 1.23e-115j)
| (0.99859651643055150742 - 1.0980815602380606635e-427j)  +/-  (2.08e-115, 2.08e-115j)
| (0.9274951474090583421 - 1.406964166624992169e-429j)  +/-  (2.8e-115, 2.8e-115j)
| (0.95582394957139775518 - 2.0541286981847647299e-429j)  +/-  (4.41e-115, 4.41e-115j)
| (-0.62802376237896618507 + 1.2407172950370935159e-432j)  +/-  (9.23e-119, 9.23e-119j)
| (-0.9274951474090583421 - 3.4699092259180339621e-428j)  +/-  (2.54e-115, 2.54e-115j)
| (-0.97731704962157666034 - 2.3552396354691941333e-434j)  +/-  (5.75e-115, 5.75e-115j)
| (-0.99859651643055150742 + 2.3917442688182123594e-447j)  +/-  (2.07e-115, 2.07e-115j)
| (0.89260246649755573921 + 1.1254199675851485862e-456j)  +/-  (1.2e-115, 1.2e-115j)
| (0.99156516842093094673 - 3.5893732235814106295e-460j)  +/-  (5.13e-115, 5.13e-115j)
| (-0.33306496018034047177 + 1.5279675955387849323e-466j)  +/-  (6.41e-123, 6.41e-123j)
| (-0.80370495897252311568 + 1.0394277604433958892e-458j)  +/-  (1.49e-116, 1.49e-116j)
| (0.97731704962157666034 - 1.480862259257291243e-462j)  +/-  (5.81e-115, 5.81e-115j)
| (0.8512614839549979707 + 1.9604233192385381275e-465j)  +/-  (4.54e-116, 4.54e-116j)
| (0.41175116146284264604 + 2.6765123547009207781e-470j)  +/-  (8.93e-122, 8.93e-122j)
| (-0.95582394957139775518 + 4.9281518566531136366e-465j)  +/-  (4.65e-115, 4.65e-115j)
| (-0.75036505635902229785 - 2.6521548239399030428e-474j)  +/-  (3.67e-117, 3.67e-117j)
| (-0.25188622569150550959 + 1.057327960603454248e-482j)  +/-  (3.68e-124, 3.68e-124j)
| (0.48748173749781995875 + 2.9350774856853224316e-480j)  +/-  (1.17e-120, 1.17e-120j)
| (0.75036505635902229785 - 1.5714084463967678861e-475j)  +/-  (3.46e-117, 3.46e-117j)
| (0.16885305857357954056 - 5.5384676830594001366e-485j)  +/-  (1.95e-125, 1.95e-125j)
| (-0.8512614839549979707 + 4.7918762158571253866e-477j)  +/-  (4.85e-116, 4.85e-116j)
| (-0.55977083107394753461 - 9.6551024092453805447e-484j)  +/-  (1.19e-119, 1.19e-119j)
| (0.0037762088409933203275 + 2.0218378865507766072e-488j)  +/-  (1.43e-128, 1.43e-128j)
| (0.69168704306035320787 + 2.6540862940838977298e-483j)  +/-  (6.57e-118, 6.57e-118j)
| (0.33306496018034047177 + 2.8936605131149939625e-489j)  +/-  (5.65e-123, 5.65e-123j)
| (-0.16885305857357954056 + 7.9936552365325454947e-489j)  +/-  (1.91e-125, 1.91e-125j)
| (-0.69168704306035320787 - 5.1577206229723327287e-484j)  +/-  (5.88e-118, 5.88e-118j)
| (-0.084775013041735301242 + 2.8404568738015247794e-491j)  +/-  (1.04e-126, 1.04e-126j)
| (0.25188622569150550959 - 5.7782950249913965809e-492j)  +/-  (3.8e-124, 3.8e-124j)
| (0.62802376237896618507 + 1.8761796555910073533e-485j)  +/-  (9.4e-119, 9.4e-119j)
| (-0.0037762088409933203275 + 1.7924016369105436668e-494j)  +/-  (1.73e-128, 1.73e-128j)
| (-0.48748173749781995875 + 6.7512689909530693965e-490j)  +/-  (1.19e-120, 1.19e-120j)
| (-0.41175116146284264604 + 1.1221967462368163928e-491j)  +/-  (1.01e-121, 1.01e-121j)
| (0.084775013041735301242 - 3.8769289578127393867e-497j)  +/-  (1.04e-126, 1.04e-126j)
| (0.55977083107394753461 - 5.5433704766650929494e-490j)  +/-  (1.2e-119, 1.2e-119j)
-------------------------------------------------
The weights are:
| (0.010546135544092251695 + 2.3763788997578727041e-420j)  +/-  (2.25e-18, 3.05e-72j)
| (0.050528990661054474595 - 2.5710771685520422504e-421j)  +/-  (8.4e-19, 1.14e-72j)
| (0.038136898609182029138 + 3.1901932298152951509e-420j)  +/-  (5.37e-19, 7.28e-73j)
| (0.003777191433692054243 + 1.3985999018970770312e-422j)  +/-  (1.39e-19, 1.89e-73j)
| (0.031635419781176342966 + 1.3078941613667507661e-421j)  +/-  (3.28e-19, 4.45e-73j)
| (0.024976912831750870255 - 9.7797330508215262717e-422j)  +/-  (2.67e-19, 3.62e-73j)
| (0.06603720081917430741 - 2.1282588180067438158e-420j)  +/-  (2.04e-20, 2.77e-74j)
| (0.031635419781176342966 - 3.9201819936957057493e-420j)  +/-  (7.11e-20, 9.64e-74j)
| (0.017932123271403414611 - 9.4790465078770004753e-420j)  +/-  (2.31e-20, 3.14e-74j)
| (0.003777191433692054243 + 3.9595145233399886874e-420j)  +/-  (1.67e-20, 2.26e-74j)
| (0.038136898609182029138 - 1.6753041129702852111e-421j)  +/-  (3.42e-21, 4.64e-75j)
| (0.010546135544092251695 - 4.1425846377266782941e-422j)  +/-  (2.46e-21, 3.33e-75j)
| (0.080019482189304586422 - 2.6847082783001811685e-420j)  +/-  (2.23e-24, 3.02e-78j)
| (0.050528990661054474595 + 2.4564079506893753628e-420j)  +/-  (4.65e-23, 6.3e-77j)
| (0.017932123271403414611 + 6.8576659170811709822e-422j)  +/-  (2.04e-21, 2.76e-75j)
| (0.044507771368404023441 + 2.0877934853379100669e-421j)  +/-  (1.66e-22, 2.26e-76j)
| (0.077280139330675098711 - 9.8576342762968011755e-421j)  +/-  (5.59e-26, 7.57e-80j)
| (0.024976912831750870255 + 5.3306247577113012973e-420j)  +/-  (1.29e-22, 1.74e-76j)
| (0.056074326068488345317 - 2.2795350549510944596e-420j)  +/-  (2.86e-24, 3.88e-78j)
| (0.082231299275164464773 + 3.240365327083995915e-420j)  +/-  (4.66e-26, 6.32e-80j)
| (0.074101866760900482024 + 7.5628585781839462045e-421j)  +/-  (2.37e-26, 3.22e-80j)
| (0.056074326068488345317 + 3.1568851831435633015e-421j)  +/-  (3.03e-25, 4.11e-79j)
| (0.083697203993168219052 + 3.1432750562428845398e-420j)  +/-  (1.92e-27, 2.6e-81j)
| (0.044507771368404023441 - 2.7406882705073678281e-420j)  +/-  (6.15e-25, 8.34e-79j)
| (0.070373801043825898304 + 2.139197988038315136e-420j)  +/-  (1.05e-26, 1.42e-80j)
| (0.04261221390115988512 + 8.3425566447335386898e-419j)  +/-  (2.95e-28, 4e-82j)
| (0.061226048244268426812 - 3.8762000059907920422e-421j)  +/-  (9.15e-28, 1.24e-81j)
| (0.080019482189304586422 + 1.3346529909299134335e-420j)  +/-  (2.69e-28, 3.65e-82j)
| (0.083697203993168219052 - 4.4334776507299572992e-420j)  +/-  (9.1e-29, 1.23e-82j)
| (0.061226048244268426812 + 2.1755346699743774066e-420j)  +/-  (4.32e-28, 5.86e-82j)
| (0.08430497487311482511 + 8.1209082273864526553e-420j)  +/-  (5.03e-29, 6.81e-83j)
| (0.082231299275164464773 - 1.9275935893285515726e-420j)  +/-  (1.44e-29, 1.95e-83j)
| (0.06603720081917430741 + 4.7775535417817812736e-421j)  +/-  (3.54e-30, 4.78e-84j)
| (0.04261221390115988512 - 8.4063401182428461087e-419j)  +/-  (1.32e-28, 1.78e-82j)
| (0.074101866760900482024 - 2.218950429872338037e-420j)  +/-  (1.14e-30, 1.54e-84j)
| (0.077280139330675098711 + 2.385756391330437687e-420j)  +/-  (1.09e-30, 1.48e-84j)
| (0.08430497487311482511 - 6.8417003797984829238e-420j)  +/-  (2.08e-30, 2.87e-84j)
| (0.070373801043825898304 - 5.9545072404441598468e-421j)  +/-  (2.12e-31, 2.72e-85j)
