I really like to have formulas displayed in typeset form in order to better serve my users' needs.
In Mathematica it is possible to Superscript (not the Power) the symbol but impossible to Subscript (not index) the symbol.
Therefore, if you try to make simple definition like
a = {Subscript[a, 1], Subscript[a, 2], Subscript[a, 3]} you receive recursion error message.
You have to use notation package (Needs["Notation"]) and to declare each subscripted symbol you want to use in a feature by means of Symbolize function. It`s very inconvenient way.