[ (3rd elementary symmetric function of 3,4,...,n+4)/(3+4+...+n+4) ].

Terms

a(0) =5a(1) =19a(2) =47a(3) =95a(4) =170a(5) =280a(6) =434a(7) =642a(8) =915a(9) =1265a(10) =1705a(11) =2249a(12) =2912a(13) =3710a(14) =4660a(15) =5780a(16) =7089a(17) =8607a(18) =10355a(19) =12355a(20) =14630a(21) =17204a(22) =20102a(23) =23350a(24) =26975a(25) =31005a(26) =35469a(27) =40397a(28) =45820a(29) =51770