Empirical: a(n) = (1/60415263063373835637355132068513997507264512000000000)*n^43 + (1/70250305887643994927157130312225578496819200000000)*n^42 + (239/40143031935796568529804074464128901998182400000000)*n^41 + (79/48954916994873864060736676175766953656320000000)*n^40 + (10909/34234207688722981860655018304732135424000000000)*n^39 + (6917/141570031795470977619250075696260710400000000)*n^38 + (179659/29676712547499798516976486456114544640000000)*n^37 + (4026797/6464987472486559089788680064414515200000000)*n^36 + (14534071301/267835195288728876576959602668601344000000000)*n^35 + (49231883/12119239605824836044206316862832640000000)*n^34 + (832692746393/3151002297514457371493642384336486400000000)*n^33 + (1696088590219/112535796339802048981915799440588800000000)*n^32 + (3899977231015301/5138731345408882093296083458326528000000000)*n^31 + (1376748405129787/40568931674280648104969079934156800000000)*n^30 + (7743842597963299/5720294633108217543557792346931200000000)*n^29 + (183622080863732219/3797092127149420265982327678566400000000)*n^28 + (5603175238313683661/3611220484561686406808367582412800000000)*n^27 + (12717391715368961587/283738752358418217677800310046720000000)*n^26 + (3701447769298439523951131/3169929341348248327896385063841955840000000)*n^25 + (21766452587025858314270959/792482335337062081974096265960488960000000)*n^24 + (600680792766354879051788551/1029197838100080625940384760987648000000000)*n^23 + (21210421092002415498249697/1893173280786101485843517118873600000000)*n^22 + (25863474913967206131732997427/133190308460010433945226263186636800000000)*n^21 + (2584222200709878687327997339/851216257075254653033400930140160000000)*n^20 + (52690553747892310030737089198567/1232328990356675486323355437498368000000000)*n^19 + (1270162375797250848144180957277/2345262784415818399577320036761600000000)*n^18 + (5798321569038770775397087391/941427800119690975036940746752000000)*n^17 + (44691970712147383079371240644703/711954773840516299871686439731200000000)*n^16 + (4545604142243027138841668553363113/7941034015913451037030348750848000000000)*n^15 + (52895717748596703750783885062551/11344334308447787195757641072640000000)*n^14 + (1945850358008881674527714984224639051/57440146048440629167852855964467200000000)*n^13 + (55211281625555433018656671788452563/251930465124739601613389719142400000000)*n^12 + (24405495447389764523964200561369157083/19374652436974021743124971257856000000000)*n^11 + (159304438898251828977727607522452157/24839297996120540696314065715200000000)*n^10 + (7823233761587955240172869987250481/271810499957548004252594995200000000)*n^9 + (178005155611611639063039251577401/1578069405101879686899302400000000)*n^8 + (412249236583690196371195142367676075739/1086783319611513654753203726745600000000)*n^7 + (211568512002989457930740558749381108823/199243608595444170038087349903360000000)*n^6 + (65879271338881683780176257510395319/27905267310286298324662093824000000)*n^5 + (125976735941578883267808434295121/32271397569718848402670448640000)*n^4 + (21536755275825402162257088463/4908324802493147497141680000)*n^3 + (460229542102669159245053/157881059949118169664000)*n^2 + (85280102604117203/101285894180671200)*n