a(n) = 729*n - 1.

Terms

a(0) =728a(1) =1457a(2) =2186a(3) =2915a(4) =3644a(5) =4373a(6) =5102a(7) =5831a(8) =6560a(9) =7289a(10) =8018a(11) =8747a(12) =9476a(13) =10205a(14) =10934a(15) =11663a(16) =12392a(17) =13121a(18) =13850a(19) =14579a(20) =15308a(21) =16037a(22) =16766a(23) =17495a(24) =18224a(25) =18953a(26) =19682a(27) =20411a(28) =21140a(29) =21869