I am currently working on a project that generates a set of matrices and I want to find their eigenvalues, but using the inbuilt Maple engine takes too long. The problem is that whenever I try to use the Matlab[eig] command I get the error:

Error, (in Matlab:-setvar) unable to store '-3.*Re(X)' when datatype=float[8]
I found out that solving symbolic matrices in MATLAB requires first defining symbols with the "sym" command but I've been unable to do that in Maple.

"From the list of positive integers 1; 2; 3; 4; : : :, remove every second number, leaving
1; 3; 5; 7; 9; : : : Since 3 is the flrst surviving number above 2 that has not been used
as the \killer", we remove every 3rd number from the remaining numbers, yielding
1; 3; 7; 9; 13; 15; 19; 21; : : :"

 I have tried using this:

A:= proc(n::integer)::list;
   local B,C,j;
   B:={seq(i,i=1..n)};
   for j from 2 by 2 to n do
       C:= {B minus {B[j]}};
   end do;
 end proc;

But I'm not getting the desired result.