Answer is 216 1^3,2^3,3^3,4^3,5^3,6^3

216,343,512

Sequence is defined by :n^3

For n=1 to n=6

If n=1 then 1 if n=2 then 8 if n=3 then 27 if n=4 then 64 if n=5 then 125 if n=6 then 216 if n=7 then 343 if n=8 then 512