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

Terms

a(0) =0a(1) =343a(2) =2744a(3) =9261a(4) =21952a(5) =42875a(6) =74088a(7) =117649a(8) =175616a(9) =250047a(10) =343000a(11) =456533a(12) =592704a(13) =753571a(14) =941192a(15) =1157625a(16) =1404928a(17) =1685159a(18) =2000376a(19) =2352637a(20) =2744000a(21) =3176523a(22) =3652264a(23) =4173281a(24) =4741632a(25) =5359375a(26) =6028568a(27) =6751269a(28) =7529536a(29) =8365427