a(n) = (6*n + 1)^3.

Terms

a(0) =1a(1) =343a(2) =2197a(3) =6859a(4) =15625a(5) =29791a(6) =50653a(7) =79507a(8) =117649a(9) =166375a(10) =226981a(11) =300763a(12) =389017a(13) =493039a(14) =614125a(15) =753571a(16) =912673a(17) =1092727a(18) =1295029a(19) =1520875a(20) =1771561a(21) =2048383a(22) =2352637a(23) =2685619a(24) =3048625a(25) =3442951a(26) =3869893a(27) =4330747a(28) =4826809a(29) =5359375