a(n) = n^4 - n^3 - n^2 - n - 1.

Terms

a(0) =-1a(1) =-3a(2) =1a(3) =41a(4) =171a(5) =469a(6) =1037a(7) =2001a(8) =3511a(9) =5741a(10) =8889a(11) =13177a(12) =18851a(13) =26181a(14) =35461a(15) =47009a(16) =61167a(17) =78301a(18) =98801a(19) =123081a(20) =151579a(21) =184757a(22) =223101a(23) =267121a(24) =317351a(25) =374349a(26) =438697a(27) =511001a(28) =591891a(29) =682021