151*n^7/315+2*n^5/9+7*n^3/45+n/7.

Terms

a(0) =0a(1) =1a(2) =70a(3) =1107a(4) =8092a(5) =38165a(6) =135954a(7) =398567a(8) =1012664a(9) =2306025a(10) =4816030a(11) =9377467a(12) =17232084a(13) =30162301a(14) =50651498a(15) =82073295a(16) =128912240a(17) =197018321a(18) =293897718a(19) =429042211a(20) =614299660a(21) =864287973a(22) =1196854978a(23) =1633586615a(24) =2200365864a(25) =2927984825a(26) =3852812366a(27) =5017519755a(28) =6471866692a(29) =8273550157