a(n) = n^5 - n^2.

Terms

a(0) =0a(1) =0a(2) =28a(3) =234a(4) =1008a(5) =3100a(6) =7740a(7) =16758a(8) =32704a(9) =58968a(10) =99900a(11) =160930a(12) =248688a(13) =371124a(14) =537628a(15) =759150a(16) =1048320a(17) =1419568a(18) =1889244a(19) =2475738a(20) =3199600a(21) =4083660a(22) =5153148a(23) =6435814a(24) =7962048a(25) =9765000a(26) =11880700a(27) =14348178a(28) =17209584a(29) =20510308