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

Terms

a(0) =27a(1) =1000a(2) =4913a(3) =13824a(4) =29791a(5) =54872a(6) =91125a(7) =140608a(8) =205379a(9) =287496a(10) =389017a(11) =512000a(12) =658503a(13) =830584a(14) =1030301a(15) =1259712a(16) =1520875a(17) =1815848a(18) =2146689a(19) =2515456a(20) =2924207a(21) =3375000a(22) =3869893a(23) =4410944a(24) =5000211