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

Terms

a(0) =0a(1) =5a(2) =28a(3) =81a(4) =176a(5) =325a(6) =540a(7) =833a(8) =1216a(9) =1701a(10) =2300a(11) =3025a(12) =3888a(13) =4901a(14) =6076a(15) =7425a(16) =8960a(17) =10693a(18) =12636a(19) =14801a(20) =17200a(21) =19845a(22) =22748a(23) =25921a(24) =29376a(25) =33125a(26) =37180a(27) =41553a(28) =46256a(29) =51301