Empirical: a(n) = (1/307955201083066820800664384184970826628464640000000000)*n^47 - (1/936034045845187905169192657097175764828160000000000)*n^46 + (1/2977838958150120589085448537954960015360000000000)*n^45 - (1/14609227025454437761838012485351684177920000000)*n^44 + (45863/3699739311641058913712223941095556382720000000000)*n^43 - (20959/11582368149144638817524851336166768640000000000)*n^42 + (47110771/200761047918507072837097423160223989760000000000)*n^41 - (1836613/69951584640594798897943353017499648000000000)*n^40 + (120108041/45620598678648781889963056315760640000000000)*n^39 - (88351891307/376662378833971994065848823940382720000000000)*n^38 + (23644115779/1251664054261655055468549730467840000000000)*n^37 - (7280254437607/5304349289411554397228881019928576000000000)*n^36 + (10430847946900127/114927567937250345273292422098452480000000000)*n^35 - (11214328994274503/2052277998879470451308793251758080000000000)*n^34 + (79283268177269491/263393967770627223697385230172160000000000)*n^33 - (5522614340619703/363660310531437981436232073216000000000)*n^32 + (6302916500833181363231/8955394904201325605711097825853440000000000)*n^31 - (4665908073508224025141/155552765085382826898207654543360000000000)*n^30 + (1676049204942253958330071/1423019739855168823846566321192960000000000)*n^29 - (686359960616094840641/16094271713451944574518820864000000000)*n^28 + (423976139410162160482108177/297422141264591935737107809566720000000000)*n^27 - (456836810569696659690591173/10380117465787040492249489080320000000000)*n^26 + (1541713611269638504891336870277/1227819608810238503940368136929280000000000)*n^25 - (5690803362312397636718269276919/171894745233433390551651539170099200000000)*n^24 + (14840862707390740726500939608689/18401117325713389963533185187840000000000)*n^23 - (127186786736577068469451126688983/7009949457414624748012641976320000000000)*n^22 + (439971788899410620091845721918113/1168324909569104124668773662720000000000)*n^21 - (8155191366855158054315969076809341/1132376450813131690063580626944000000000)*n^20 + (1143672185298566741035598530128112867/9027615830848110489628122808320000000000)*n^19 - (19884827721404899049046344162987835949/9722047817836426681137978408960000000000)*n^18 + (1110550938573999388479854440494897909629/36741549852062130841845403484160000000000)*n^17 - (9839448498430653623042146226226908889349/24144447045640828838926979432448000000000)*n^16 + (240164088854817094179144285486899601990383/48100265598737588702549841838080000000000)*n^15 - (1910564675540435116741616003599965433646369/34533524019606473940292194140160000000000)*n^14 + (185404565052663454778426301186007119913169/336365493697465655262586306560000000000)*n^13 - (4617468713082064763867110480345301016226291/941823382352903834735241658368000000000)*n^12 + (138396898353649161114077516575169848328470817123/3586384954717995060685572298260480000000000)*n^11 - (34047521519584622616244452911481457649615907929/128085176954214109310199010652160000000000)*n^10 + (89920020560824771963253862402307968757246865429/56926745312984048582310671400960000000000)*n^9 - (16229903681194826869679456194879993778531121221/2043524190722504308082947178496000000000)*n^8 + (234435114225591630382135792373310769437906439601/7131656148932168308506142444953600000000)*n^7 - (2747019840123988100067761034853594011935042239/25600816944884706748483588263936000000)*n^6 + (58947898230761890614786486257391954473256973/230850056010300539947127465472000000)*n^5 - (880207538230356195921587492654500824580418027/2433819161937168549728286707404800000)*n^4 + (3807571065399040382770688596795715959873/336567103923490119310669758720000)*n^3 + (3546051219235344612269329876279983851/3362308730504396796310387200)*n^2 - (254802624835227858983222670257/147573547821237938400)*n + 714490967 for n>13