a(n) = (12*n + 9)^3.

Terms

a(0) =729a(1) =9261a(2) =35937a(3) =91125a(4) =185193a(5) =328509a(6) =531441a(7) =804357a(8) =1157625a(9) =1601613a(10) =2146689a(11) =2803221a(12) =3581577a(13) =4492125a(14) =5545233a(15) =6751269a(16) =8120601a(17) =9663597a(18) =11390625a(19) =13312053a(20) =15438249a(21) =17779581a(22) =20346417a(23) =23149125a(24) =26198073a(25) =29503629a(26) =33076161a(27) =36926037a(28) =41063625a(29) =45499293