Empirical: a(n) = (1/7353420799762759680000000)*n^30 + (13/490228053317517312000000)*n^29 + (1787413/659931481843536494592000000)*n^28 + (523777/2856846241746911232000000)*n^27 + (36467381767/4032914611266056355840000000)*n^26 + (1418850019/4136322678221596262400000)*n^25 + (55224658519/5318129157713480908800000)*n^24 + (3195876850889/12408968034664788787200000)*n^23 + (43151840501093/8092805239998775296000000)*n^22 + (269404184843/2885135557931827200000)*n^21 + (68470171382881/49047304484841062400000)*n^20 + (293216145660553/16349101494947020800000)*n^19 + (5884606572181/29581020758016000000)*n^18 + (4934186275981861/2581437078149529600000)*n^17 + (148366700781473701/9306189130471833600000)*n^16 + (2509137249704430971/21714441304434278400000)*n^15 + (20986725057214719643/28839492357451776000000)*n^14 + (4705830351060354823/1183158660818534400000)*n^13 + (815972824689457410401/43354313785707724800000)*n^12 + (11038552383644372519/143693274857932800000)*n^11 + (46389978525580705826513/172431929829519360000000)*n^10 + (4614822960261861794737/5747730994317312000000)*n^9 + (275354863997978840863/136005980318208000000)*n^8 + (10448353961312528488691/2448107645727744000000)*n^7 + (35671549722138690560953/4808782875536640000000)*n^6 + (22924327332841510297/2200096740441600000)*n^5 + (280140372934030499503/24311068981879680000)*n^4 + (197117936454903073/20259224151566400)*n^3 + (3670903703130173/587752601436000)*n^2 + (4877294953/2218180536)*n + 1