I once had the problem that I was writing about a chessboard of an arbitrary length with the usual notation of numbers and letters. I now wanted to do a little sketch of the start and ending of this infinite chessboard. For the numbers, you can name the chessboard columns $1, 2, 3, ..., n-2, n-1, n$, of course. But how would you do that with letters for the rows?
I myself came up with the idea of using the last greek letters: $a, b, c, ... \chi, \psi, \omega$. After a little research, I just found attempts that showed just the beginning of the chessboard, where they started to duplicate the letters: $a, b, c, ... z, aa, bb, cc, ... zz, aaa, bbb ...$ (picture on Wikipedia). Similar things happen of course in Microsoft Excel: $a, b, c, ... z, aa, ab, ac, ... az, ba, bb ...$. Still, these sources never show the "end" of an infinite/arbitrary length chessboard (or a similar table).
Are there any examples in literature of how this problem is handled?
Perhaps the best thing is just to invent a notation that fits all your wishes and then explain it to the reader. You could say, for example, "We'll let $\omega$ represent the letter corresponding to the last column; for example, on a regular chessboard, $\omega$ would mean $h$, whereas on a chessboard with $n=53$, $\omega$ would mean $ba$." (if you use the Excel numbering) "Now consider the columns $a,b,\dots,\omega$ and the rows $1,2,\dots,n$"