a(n) = n^2*(2*n + 5).

Terms

a(0) =0a(1) =7a(2) =36a(3) =99a(4) =208a(5) =375a(6) =612a(7) =931a(8) =1344a(9) =1863a(10) =2500a(11) =3267a(12) =4176a(13) =5239a(14) =6468a(15) =7875a(16) =9472a(17) =11271a(18) =13284a(19) =15523a(20) =18000a(21) =20727a(22) =23716a(23) =26979a(24) =30528a(25) =34375a(26) =38532a(27) =43011a(28) =47824a(29) =52983