a(1) = 1, a(2) = 2; for n >= 3, a(n) = (n-1)^3 - a(n-1) - a(n-2).

Terms

a(0) =1a(1) =2a(2) =5a(3) =20a(4) =39a(5) =66a(6) =111a(7) =166a(8) =235a(9) =328a(10) =437a(11) =566a(12) =725a(13) =906a(14) =1113a(15) =1356a(16) =1627a(17) =1930a(18) =2275a(19) =2654a(20) =3071a(21) =3536a(22) =4041a(23) =4590a(24) =5193a(25) =5842a(26) =6541a(27) =7300a(28) =8111a(29) =8978