Empirical: a(n) = (1/304888344611713860501504000000)*n^28 + (1/806582922253211271168000000)*n^27 + (83/372269041039943663616000000)*n^26 + (1579/62044840173323943936000000)*n^25 + (22073/10636258315426961817600000)*n^24 + (69571/539520349333251686400000)*n^23 + (432038609/67979564015989712486400000)*n^22 + (12516827/49047304484841062400000)*n^21 + (2503118221/294283826909046374400000)*n^20 + (615527777/2581437078149529600000)*n^19 + (138114216199/24339263879695564800000)*n^18 + (192686181617/1670341638802636800000)*n^17 + (5500322706942689/2736019604358719078400000)*n^16 + (652933387868807/21714441304434278400000)*n^15 + (3865572994866421/10022049832815820800000)*n^14 + (7068059658018713/1670341638802636800000)*n^13 + (240368503095136219/6084815969923891200000)*n^12 + (201046094664277679/645359269537382400000)*n^11 + (2383070883176496495373/1158742568454370099200000)*n^10 + (1639298416173508583/145974120490598400000)*n^9 + (468126500135529162959/9366672731480064000000)*n^8 + (278435638503449075567/1561112121913344000000)*n^7 + (19612198878575842753/39255370412544000000)*n^6 + (198035108395804908821/187008222937536000000)*n^5 + (815295333931190132561/510532448619473280000)*n^4 + (842574592463657441/540245977375104000)*n^3 + (200570693201/235586070720)*n^2 + (230053/1201200)*n