Empirical: a(n) = (1/135676837793935726492471787520000000)*n^33 + (1/265252859812191058636308480000000)*n^32 + (199/220254606808337218331934720000000)*n^31 + (2999/22104404984349254886359040000000)*n^30 + (439883/30606099209098968304189440000000)*n^29 + (153977/134509563799285526691840000000)*n^28 + (29633743/415756833561427991592960000000)*n^27 + (104338919/29316186981895563509760000000)*n^26 + (1457450473/10051264108078478917632000000)*n^25 + (38132750323/7817649861838816935936000000)*n^24 + (105740145961787/773947336322042876657664000000)*n^23 + (408617840453/127461682529980710912000000)*n^22 + (2517439348125781/39768044949353981804544000000)*n^21 + (6995953057910249/6628007491558996967424000000)*n^20 + (84639299043362467/5681149278479140257792000000)*n^19 + (3456821351907421/19380138864207593472000000)*n^18 + (13287636762776347/7318374116553916416000000)*n^17 + (22008964253450050087/1395369998222946729984000000)*n^16 + (14047754460659708335571/119304134848061945413632000000)*n^15 + (89953991873476431577/117656937719982194688000000)*n^14 + (6102289862768177345921/1386671051699790151680000000)*n^13 + (861812411439337770479/37488730155876679680000000)*n^12 + (7339480874535445852388033/65961420709265017896960000000)*n^11 + (5483400354159495558213299/10993570118210836316160000000)*n^10 + (49092632373327072488906029/23819401922790145351680000000)*n^9 + (9819769946282087858863/1292285260568041740000000)*n^8 + (5098856437605746989699/204591853250104320000000)*n^7 + (1471722138721082086269283/18379168150301038080000000)*n^6 + (489888969724195175777491/2049984139841269632000000)*n^5 + (45631450198467569347061/88832646059788350720000)*n^4 + (82602298061059866500921/72123648348542446656000)*n^3 + (252155121263429/132844367656000)*n^2 + (3427355501789/1640949464700)*n + 1