a(n) = (4*n + 1)^3.

Terms

a(0) =1a(1) =125a(2) =729a(3) =2197a(4) =4913a(5) =9261a(6) =15625a(7) =24389a(8) =35937a(9) =50653a(10) =68921a(11) =91125a(12) =117649a(13) =148877a(14) =185193a(15) =226981a(16) =274625a(17) =328509a(18) =389017a(19) =456533a(20) =531441a(21) =614125a(22) =704969a(23) =804357a(24) =912673a(25) =1030301a(26) =1157625a(27) =1295029a(28) =1442897a(29) =1601613