Empirical: a(n) = (1/7353420799762759680000000)*n^30 + (1/70032579045359616000000)*n^29 + (44267/43995432122902432972800000)*n^28 + (10719031/219977160614512164864000000)*n^27 + (7405991867/4032914611266056355840000000)*n^26 + (5041111/89530793900900352000000)*n^25 + (841340921/572721601599913328640000)*n^24 + (8426535779/253244245605403852800000)*n^23 + (199084308659/299733527407362048000000)*n^22 + (576371647253/49047304484841062400000)*n^21 + (1828262507677/9809460896968212480000)*n^20 + (6128122861981/2335585927849574400000)*n^19 + (1284061338761629/38721556172242944000000)*n^18 + (134164296772141/368776725449932800000)*n^17 + (16965781994905333/4342888260886855680000)*n^16 + (67651063057854779/1974040118584934400000)*n^15 + (154368557984502723413/461431877719228416000000)*n^14 + (175799680765071469/67609066332487680000)*n^13 + (25593540025751119297/1167231524999823360000)*n^12 + (16444443670432142437/119433371310489600000)*n^11 + (45241297909591903187921/57477309943173120000000)*n^10 + (39287845815991390936771/11495461988634624000000)*n^9 + (16471812951461465508979/1468864587436646400000)*n^8 + (3363527623529806213337/131148623878272000000)*n^7 + (2125295394991708080782923/16830740064378240000000)*n^6 - (8270939934599280804409/14572069319808000000)*n^5 + (241055486878548366683039/48622137963759360000)*n^4 - (11352393983286118617209/810368966062656000)*n^3 + (3535588242068396838923/279770238283536000)*n^2 - (12654095890387037/776363187600)*n + 49582 for n>5