a(n) = n^5-n+1.

Terms

a(0) =1a(1) =1a(2) =31a(3) =241a(4) =1021a(5) =3121a(6) =7771a(7) =16801a(8) =32761a(9) =59041a(10) =99991a(11) =161041a(12) =248821a(13) =371281a(14) =537811a(15) =759361a(16) =1048561a(17) =1419841a(18) =1889551a(19) =2476081a(20) =3199981a(21) =4084081a(22) =5153611a(23) =6436321a(24) =7962601a(25) =9765601a(26) =11881351a(27) =14348881a(28) =17210341a(29) =20511121