a(n) = n^3 - 2*n^2 + 2*n + 1.

Terms

a(0) =2a(1) =5a(2) =16a(3) =41a(4) =86a(5) =157a(6) =260a(7) =401a(8) =586a(9) =821a(10) =1112a(11) =1465a(12) =1886a(13) =2381a(14) =2956a(15) =3617a(16) =4370a(17) =5221a(18) =6176a(19) =7241a(20) =8422a(21) =9725a(22) =11156a(23) =12721a(24) =14426a(25) =16277a(26) =18280a(27) =20441a(28) =22766a(29) =25261