a(n) = (7*n + 6)^3.

Terms

a(0) =216a(1) =2197a(2) =8000a(3) =19683a(4) =39304a(5) =68921a(6) =110592a(7) =166375a(8) =238328a(9) =328509a(10) =438976a(11) =571787a(12) =729000a(13) =912673a(14) =1124864a(15) =1367631a(16) =1643032a(17) =1953125a(18) =2299968a(19) =2685619a(20) =3112136a(21) =3581577a(22) =4096000a(23) =4657463a(24) =5268024