Cube analog to Keith numbers.

Terms

a(0) =1a(1) =8a(2) =17a(3) =18a(4) =26a(5) =27a(6) =44a(7) =55a(8) =63a(9) =80a(10) =105a(11) =187a(12) =326a(13) =776a(14) =1095a(15) =2196a(16) =6338a(17) =13031a(18) =13131a(19) =25562a(20) =27223a(21) =70825a(22) =140791a(23) =553076a(24) =632489a(25) =1402680a(26) =1404312a(27) =3183253a(28) =11311424a(29) =50783292