As you know, the letter n is used to mean an unspecified variable, but if you wish to write "A to n" (like "A to Z," but to mean "A to anything") then the letter N would be misleading (as it might be taken to indicate the exact range between the letters A and N), so this is how to do it, as revealed in A Little Spasm at the Home of Wolfgang Mozart. Being a Sketch Printed from What Is (Supposedly) the Original Manuscript of the Little Journey to Mozart, 1901.