Odd cubes: a(n) = (2*n + 1)^3.

Terms

a(0) =1a(1) =27a(2) =125a(3) =343a(4) =729a(5) =1331a(6) =2197a(7) =3375a(8) =4913a(9) =6859a(10) =9261a(11) =12167a(12) =15625a(13) =19683a(14) =24389a(15) =29791a(16) =35937a(17) =42875a(18) =50653a(19) =59319a(20) =68921a(21) =79507a(22) =91125a(23) =103823a(24) =117649a(25) =132651a(26) =148877a(27) =166375a(28) =185193a(29) =205379