Starting with polynomial:
P : t^15 - 105*t^13 + 4095*t^11 - 75075*t^9 + 675675*t^7 - 2837835*t^5 + 4729725*t^3 - 2027025*t
Extension levels are: 15 30
-------------------------------------------------
Trying to find an order 30 Kronrod extension for:
P1 : t^15 - 105*t^13 + 4095*t^11 - 75075*t^9 + 675675*t^7 - 2837835*t^5 + 4729725*t^3 - 2027025*t
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : t^45 - 550629093772008855/697360773473122*t^43 + 197784449861096282695/697360773473122*t^41 - 128729168455176283047725/2092082320419366*t^39 + 119622956296494199863034175/13249854695989318*t^37 - 6297650584543776742608950990/6624927347994659*t^35 + 25130020360774474481097259934800/337871294747727609*t^33 - 2380924899048905426491396438225/538869688592867*t^31 + 2066978079179319956476760635372125/10238524083264473*t^29 - 73151968496201688210711782934928000/10238524083264473*t^27 + 2009906327847417725064783875559628500/10238524083264473*t^25 - 42800282463899454974180908541554106250/10238524083264473*t^23 + 702516128535022323429005219461697175000/10238524083264473*t^21 - 463423815220866362067122659265882596875/538869688592867*t^19 + 257341551381347878452359428518807421875/31698216976051*t^17 - 1795390169041168642642665080429510844375/31698216976051*t^15 + 9021891577102498546165361558466313143750/31698216976051*t^13 - 63052527533084922191305725448382853196875/63396433952102*t^11 + 145878750311630257193266171345207336171875/63396433952102*t^9 - 207987495270228335527795184857486243734375/63396433952102*t^7 + 163240501644024033538445231932894673240625/63396433952102*t^5 - 28835277637464415939462756324775300109375/31698216976051*t^3 + 2888447515571841983999462024328605203125/31698216976051*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:
| (5.1900935913047811995 - 5.1840551713140096893e-544j)  +/-  (5.12e-245, 5.12e-245j)
| (4.6819266920986158603 - 9.8368213275190705723e-555j)  +/-  (1.58e-245, 1.58e-245j)
| (-10.24539621420218123 + 3.7952932111522104843e-568j)  +/-  (2.26e-246, 2.26e-246j)
| (-11.216955441779556045 + 1.0665462244906600189e-571j)  +/-  (1.69e-247, 1.69e-247j)
| (10.24539621420218123 + 3.0600249278534097974e-568j)  +/-  (2.2e-246, 2.2e-246j)
| (-8.0499614233567160304 - 1.5943635925200471811e-594j)  +/-  (1.1e-244, 1.1e-244j)
| (6.8169911038474186602 - 6.6278151706149558198e-649j)  +/-  (5.75e-244, 5.75e-244j)
| (6.3212030668333740528 + 4.0576501542129813925e-700j)  +/-  (4.3e-243, 4.3e-243j)
| (-6.8169911038474186602 + 7.2359725566173917155e-719j)  +/-  (6.99e-244, 6.99e-244j)
| (11.216955441779556045 + 5.0119977662738334741e-718j)  +/-  (1.65e-247, 1.65e-247j)
| (9.4387392744435983788 + 2.594104833475528484e-722j)  +/-  (1.16e-245, 1.16e-245j)
| (-3.7330358918505371025 - 2.6277644153872197574e-739j)  +/-  (1.62e-246, 1.62e-246j)
| (-8.7170816204734543437 + 9.3783204985419404043e-735j)  +/-  (4.38e-245, 4.38e-245j)
| (-1.6067100690287297365 - 2.5929000082592190184e-741j)  +/-  (2.14e-250, 2.14e-250j)
| (-5.1900935913047811995 + 1.3789626403635274385e-734j)  +/-  (5.3e-245, 5.3e-245j)
| (2.4324368270097580412 + 1.4117803885431730565e-738j)  +/-  (1.22e-248, 1.22e-248j)
| (4.1962077112690156596 - 3.4755563876448902956e-734j)  +/-  (5.22e-246, 5.22e-246j)
| (-3.2890824243987663889 - 9.7949008556525129072e-746j)  +/-  (3.21e-247, 3.21e-247j)
| (-9.4387392744435983788 - 6.3610858888693632114e-742j)  +/-  (1.15e-245, 1.15e-245j)
| (8.7170816204734543437 - 1.3139909618990687368e-741j)  +/-  (3.98e-245, 3.98e-245j)
| (6.3639478888298383177 - 2.8095489911173090467e-755j)  +/-  (4.57e-243, 4.57e-243j)
| (-2.4324368270097580412 - 1.00237581286408219e-774j)  +/-  (1.22e-248, 1.22e-248j)
| (5.7212164898145151111 + 4.9022158839406852273e-767j)  +/-  (1.75e-244, 1.75e-244j)
| (-4.6819266920986158603 + 1.473683771196089436e-774j)  +/-  (1.74e-245, 1.74e-245j)
| (-7.4212948068331219679 - 6.6748344360194024118e-775j)  +/-  (2.17e-244, 2.17e-244j)
| (-2.857199067463892674 - 5.6358677823419792653e-780j)  +/-  (7.64e-248, 7.64e-248j)
| (0.79912906832454799942 - 5.4175906952572316651e-782j)  +/-  (1.74e-252, 1.74e-252j)
| (-5.7212164898145151111 + 1.3805645764212158306e-773j)  +/-  (1.74e-244, 1.74e-244j)
| (-6.3212030668333740528 + 2.7009322082620719864e-771j)  +/-  (4.8e-243, 4.8e-243j)
| (-0.79912906832454799942 + 4.7933871580959634849e-782j)  +/-  (1.74e-252, 1.74e-252j)
| (3.2890824243987663889 + 1.0964549640886596583e-776j)  +/-  (3.62e-247, 3.62e-247j)
| (-0.39779419887098859769 - 1.3146635638374846148e-782j)  +/-  (1.13e-253, 1.13e-253j)
| (2.0153753091319804176 - 8.5666666659464103458e-779j)  +/-  (1.72e-249, 1.72e-249j)
| (-2.0153753091319804176 + 8.2401080878660707714e-779j)  +/-  (1.71e-249, 1.71e-249j)
| (-6.3639478888298383177 - 6.42390394617900896e-771j)  +/-  (5.21e-243, 5.21e-243j)
| (3.7330358918505371025 + 1.4157383674053022691e-775j)  +/-  (1.52e-246, 1.52e-246j)
| (8.0499614233567160304 - 6.7367814164502681996e-772j)  +/-  (1.07e-244, 1.07e-244j)
| (1.6067100690287297365 - 7.8746885853384617159e-789j)  +/-  (2.14e-250, 2.14e-250j)
| (2.857199067463892674 - 9.8425812273741145039e-786j)  +/-  (7.13e-248, 7.13e-248j)
| (-1.2025424825512683259 + 9.5836326601148219736e-790j)  +/-  (2.32e-251, 2.32e-251j)
| (1.1590749604427963283e-800 + 1.2615075915539520185e-800j)  +/-  (7.71e-799, 7.71e-799j)
| (-4.1962077112690156596 + 1.7101990015446157262e-784j)  +/-  (5.32e-246, 5.32e-246j)
| (1.2025424825512683259 + 5.3376946747072771358e-790j)  +/-  (2.24e-251, 2.24e-251j)
| (0.39779419887098859769 - 1.6147954144234572958e-791j)  +/-  (1.13e-253, 1.13e-253j)
| (7.4212948068331219679 - 1.0475670316973079692e-780j)  +/-  (2.24e-244, 2.24e-244j)
-------------------------------------------------
The weights are:
| (2.9308022032766894603e-07 + 4.3828323612230389423e-550j)  +/-  (2.65e-69, 7.39e-191j)
| (3.4463108288057884156e-06 - 1.3004067691631347539e-549j)  +/-  (2.28e-67, 6.36e-189j)
| (5.5667845281646397854e-24 - 2.6441215046813203668e-562j)  +/-  (8.62e-84, 2.4e-205j)
| (2.1325908489046682181e-28 + 7.2804723093783426429e-565j)  +/-  (1.5e-85, 4.19e-207j)
| (5.5667845281646397854e-24 + 8.0733664381304632409e-562j)  +/-  (1.08e-84, 3e-206j)
| (2.1850479624358484216e-15 + 5.7753585914737910418e-557j)  +/-  (2.49e-80, 6.94e-202j)
| (1.952778591317080058e-11 - 4.8074648406616029353e-553j)  +/-  (4.58e-77, 1.28e-198j)
| (1.1759275324280052634e-09 - 5.3243583094704028764e-551j)  +/-  (1.2e-75, 3.34e-197j)
| (1.952778591317080058e-11 + 6.5138647634867690433e-554j)  +/-  (3.34e-79, 9.29e-201j)
| (2.1325908489046682181e-28 - 1.981977837359017451e-564j)  +/-  (2.57e-87, 7.16e-209j)
| (1.3627487975107202258e-20 - 9.669252311730385196e-560j)  +/-  (9.03e-84, 2.51e-205j)
| (0.00017003488408684089511 - 1.0765854781507568932e-549j)  +/-  (4.49e-72, 1.25e-193j)
| (8.707550100417534358e-18 - 1.5537918018414072029e-558j)  +/-  (1.3e-83, 3.62e-205j)
| (0.044495474883324368683 + 9.4529110951599737217e-548j)  +/-  (1.04e-61, 2.89e-183j)
| (2.9308022032766894603e-07 + 1.4636961790659975756e-551j)  +/-  (5.61e-77, 1.56e-198j)
| (0.008723388597069442367 + 6.4957465098495884833e-548j)  +/-  (7.95e-68, 2.22e-189j)
| (2.8404918092036361049e-05 + 2.6980032721753467306e-549j)  +/-  (1.34e-73, 3.74e-195j)
| (0.00077970853262210822283 + 3.4793703498817643484e-549j)  +/-  (8.59e-72, 2.39e-193j)
| (1.3627487975107202258e-20 + 2.8082368204027407656e-560j)  +/-  (2.7e-85, 7.52e-207j)
| (8.707550100417534358e-18 + 6.126716238418311246e-558j)  +/-  (1.78e-84, 4.97e-206j)
| (-5.6548142413051097206e-10 + 4.4774985006364915583e-551j)  +/-  (4.44e-78, 1.24e-199j)
| (0.008723388597069442367 + 2.3500121769452137239e-548j)  +/-  (3.67e-71, 1.02e-192j)
| (1.6943707441595076123e-08 + 6.9337975187722824086e-551j)  +/-  (6.87e-78, 1.91e-199j)
| (3.4463108288057884156e-06 - 6.6939051646651197105e-551j)  +/-  (5.59e-78, 1.56e-199j)
| (2.6863845588905358027e-13 - 1.7531854357531953317e-555j)  +/-  (2.11e-83, 5.89e-205j)
| (0.0028818451111410913979 - 9.6630737290682821974e-549j)  +/-  (3.84e-74, 1.07e-195j)
| (0.11679688879593241715 + 3.0661958264683942883e-547j)  +/-  (3.39e-71, 9.45e-193j)
| (1.6943707441595076123e-08 - 3.3751205019100283737e-552j)  +/-  (7.29e-81, 2.03e-202j)
| (1.1759275324280052634e-09 + 5.2317582577316721082e-552j)  +/-  (3.62e-82, 1.01e-203j)
| (0.11679688879593241715 + 2.2479640280049946211e-547j)  +/-  (3.92e-74, 1.09e-195j)
| (0.00077970853262210822283 + 1.5519211109121485281e-548j)  +/-  (2.55e-80, 7.08e-202j)
| (0.14721874870296644782 - 2.9175503161294455288e-547j)  +/-  (6.92e-75, 1.93e-196j)
| (0.021599864720378504235 - 1.1440006745905198215e-547j)  +/-  (1.01e-77, 2.81e-199j)
| (0.021599864720378504235 - 5.040449007061514823e-548j)  +/-  (2.05e-76, 5.71e-198j)
| (-5.6548142413051097206e-10 - 4.5489977390829323089e-552j)  +/-  (2.92e-82, 8.13e-204j)
| (0.00017003488408684089511 - 6.5930893639887688617e-549j)  +/-  (3.78e-81, 1.05e-202j)
| (2.1850479624358484216e-15 - 2.673762214612397094e-556j)  +/-  (1.61e-89, 4.46e-211j)
| (0.044495474883324368683 + 1.7929864423583373071e-547j)  +/-  (2.68e-79, 7.1e-201j)
| (0.0028818451111410913979 - 3.3332660986405214281e-548j)  +/-  (1.23e-80, 3.27e-202j)
| (0.078133128109239394418 - 1.5485254355321309611e-547j)  +/-  (9.83e-79, 2.57e-200j)
| (0.15833751156029209391 + 3.3569263399620225782e-547j)  +/-  (1.52e-78, 3.77e-200j)
| (2.8404918092036361049e-05 + 2.8568306835687518637e-550j)  +/-  (2.16e-82, 5.65e-204j)
| (0.078133128109239394418 - 2.4825160331375566159e-547j)  +/-  (9.67e-80, 2.34e-201j)
| (0.14721874870296644782 - 3.4019042746885058406e-547j)  +/-  (2.38e-79, 4.87e-201j)
| (2.6863845588905358027e-13 + 9.9095062832621444779e-555j)  +/-  (3.03e-88, 8.64e-210j)
