a(n) = (10*n + 3)^6.

Terms

a(0) =729a(1) =4826809a(2) =148035889a(3) =1291467969a(4) =6321363049a(5) =22164361129a(6) =62523502209a(7) =151334226289a(8) =326940373369a(9) =646990183449