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

Terms

a(0) =0a(1) =64a(2) =512a(3) =1728a(4) =4096a(5) =8000a(6) =13824a(7) =21952a(8) =32768a(9) =46656a(10) =64000a(11) =85184a(12) =110592a(13) =140608a(14) =175616a(15) =216000a(16) =262144a(17) =314432a(18) =373248a(19) =438976a(20) =512000a(21) =592704a(22) =681472a(23) =778688a(24) =884736a(25) =1000000a(26) =1124864a(27) =1259712a(28) =1404928a(29) =1560896