For several releases now you have been able to use sym() to generate the names directly.
A = sym('a',[m,n]) creates an m-by-n symbolic matrix filled with automatically generated elements. The generated elements do not appear in the MATLAB workspace.
When you use this syntax to create a vector, it generates the elements by using the prefix a and attaching the numbers from 1 to m or n to it. For example, A = sym('a',[1,3]) creates a row vector A = [a1,a2,a3].
When you use this syntax to create a matrix, it generates the elements of the form ai_j, where i = 1:m and j = 1:n. For example, A = sym('a',[2 2]) generates the 2-by-2 symbolic matrix A = [a1_1, a1_2; a2_1, a2_2].
To specify another form for generated names of matrix elements, use combinations of '%d' and the prefix a. For example, A = sym('a_%d',[1 3]) generates a row vector A = [a_1, a_2, a_3], and AB = sym('a%db%d',[2 2]) generates the 2-by-2 symbolic matrix AB = [a1b1, a1b2; a2b1, a2b2].
