Empirical: a(n) = (1/258623241511168180642964355153611979969197632389120000000000)*n^47 + (1/1375655539953022237462576357200063723240412938240000000000)*n^46 + (1/7974814724365346304130877433043847670958915584000000000)*n^45 + (47/1993703681091336576032719358260961917739728896000000000)*n^44 + (97/36988936569412552431033754327661631126896640000000000)*n^43 + (6649/21075091766293198478147139093667673549045760000000000)*n^42 + (1675493/50580220239103676347553133824802416517709824000000000)*n^41 + (855059/308415977067705343582641059907331808034816000000000)*n^40 + (43658353/178791870763887155700081773859322787266560000000000)*n^39 + (47792159/2726931715894830624072865251170042511360000000000)*n^38 + (63509053/52324283751606073328074827977337958563840000000)*n^37 + (89649767/1189806348301853278639955158008594432000000000)*n^36 + (6580857659773/1508079546472599030676143162775893442560000000000)*n^35 + (2804620066673917/12064636371780792245409145302207147540480000000000)*n^34 + (62207648323619/5734824181476312416118429139492405248000000000)*n^33 + (45532195436753/84335649727592829648800428521947136000000000)*n^32 + (5306777877195120643/278548603100278031640037986775345397760000000000)*n^31 + (491488996371096253/542224755756937213982276392499281920000000000)*n^30 + (25759422749109624377237/1075557025519460657655243452161575616512000000000)*n^29 + (2156786747252552304079/1854408664688725271819385262347544166400000000)*n^28 + (6102667154900508894294893/339974921859599633166887298097049763840000000000)*n^27 + (15718736998969169186245409/13075958533061524352572588388348067840000000000)*n^26 + (197124456658846087140739643/34371091001190292583905089477943492608000000000)*n^25 + (4326083307580539523427142199/4626877634775616309371838968184700928000000000)*n^24 - (1310231046571540619338657776719/370881732937745054363877052469508833280000000000)*n^23 + (56961132394795940765440180604957/92720433234436263590969263117377208320000000000)*n^22 - (22352762259142377756648422908093/3090681107814542119698975437245906944000000000)*n^21 + (501579379651649032748397952474127/1545340553907271059849487718622953472000000000)*n^20 - (7453632030921795943107131084246359/1684769776816197772016358790979911680000000000)*n^19 + (82940329364277671782751237042956141/737086777357086525257156971053711360000000000)*n^18 - (908765661413286856722625639682131/602653271448449101133369230648934400000000)*n^17 + (7204367619316661079174001777955750843/260913416344740316725976325739773952000000000)*n^16 - (8589037478282450617030771837093623180137/27927399008751833901410058569923952640000000000)*n^15 + (1648972421204094954696088263291127379897/537065365552919882719424203267768320000000000)*n^14 - (2390246681427503291617502101202505563/697487487731064782752498965282816000000000)*n^13 - (24061914692046437972615125103758293007/62595030950223762554711445602304000000000)*n^12 + (116923674863787775005618524289059767276398041/12394546403505390929729337862788218880000000000)*n^11 - (90892842782317926303593909665222986642451/659565049143539321505392606576640000000000)*n^10 + (8934407347171955591887443888532940958231137/5738215927548792097096915677216768000000000)*n^9 - (165181343930602098770266506178135295129857/11954616515726650202285240994201600000000)*n^8 + (30173957190692962369605096400957885114878667/308087545633869670927465353621995520000000)*n^7 - (49352477010092934925154485853464487098477783/89858867476545320687177394806415360000000)*n^6 + (44523312849745848790848690818209585038747127/18399672864244994235945847507980288000000)*n^5 - (1276367940851691526291010711642249258369/156459803267389406768247002618880000)*n^4 + (73240482608821757972274672925876532939/3634924722373693288555233394176000)*n^3 - (14653660860781970511271655264741/434781301358327171936688000)*n^2 + (3688095386525112831620273/110680160865928453800)*n - 14155 for n>3