a(n) = 2/15 * (32*n^5 + 80*n^4 + 40*n^3 - 20*n^2 + 3*n).

Terms

a(0) =18a(1) =340a(2) =2022a(3) =7400a(4) =20602a(5) =48060a(6) =99022a(7) =186064a(8) =325602a(9) =538404a(10) =850102a(11) =1291704a(12) =1900106a(13) =2718604a(14) =3797406a(15) =5194144a(16) =6974386a(17) =9212148a(18) =11990406a(19) =15401608a(20) =19548186a(21) =24543068a(22) =30510190a(23) =37585008a(24) =45915010a(25) =55660228a(26) =66993750a(27) =80102232a(28) =95186410a(29) =112461612