Assume I wish to refer to the i-th object, or the n-th function out of some set, where i and n are letters and not numbers (as in "Multiply the $j$th row with the $i$th column and store the result in the $k$th memory cell, where $k=i+j$")
How do you suggest to write it?
$n$th is just confusing, $n$-th seems weird, and $n^{\text{th}}$, which is my current choice, is (pardon me) simply ugly.
Any suggestions?

$n^{\text{\tiny th}}$. – Ran G. Feb 14 '11 at 02:40multiply row~$j$ with column~$i$" or "multiply the $j$-th row with the $k$-th column". The "th" at exponent is too ambiguous in a math context (and simply ugly in general). – egreg Jun 05 '12 at 10:54The $(i+j)$th cell is ...– yo' Jan 10 '13 at 10:21