a(n) = n*(5n^2 + 3n + 4) / 6.

Terms

a(0) =0a(1) =2a(2) =10a(3) =29a(4) =64a(5) =120a(6) =202a(7) =315a(8) =464a(9) =654a(10) =890a(11) =1177a(12) =1520a(13) =1924a(14) =2394a(15) =2935a(16) =3552a(17) =4250a(18) =5034a(19) =5909a(20) =6880a(21) =7952a(22) =9130a(23) =10419a(24) =11824a(25) =13350a(26) =15002a(27) =16785a(28) =18704a(29) =20764