a(n) = (8*n)^5.

Terms

a(0) =0a(1) =32768a(2) =1048576a(3) =7962624a(4) =33554432a(5) =102400000a(6) =254803968a(7) =550731776a(8) =1073741824a(9) =1934917632a(10) =3276800000a(11) =5277319168a(12) =8153726976a(13) =12166529024a(14) =17623416832a(15) =24883200000a(16) =34359738368a(17) =46525874176