a(n) = (n - 1)*(n^2 + n - 1).

Terms

a(0) =1a(1) =0a(2) =5a(3) =22a(4) =57a(5) =116a(6) =205a(7) =330a(8) =497a(9) =712a(10) =981a(11) =1310a(12) =1705a(13) =2172a(14) =2717a(15) =3346a(16) =4065a(17) =4880a(18) =5797a(19) =6822a(20) =7961a(21) =9220a(22) =10605a(23) =12122a(24) =13777a(25) =15576a(26) =17525a(27) =19630a(28) =21897a(29) =24332