Some discoveries:

-Because "342" was used so often in the book (Room Number at the hotel, Lawn Street), I feel that it is appropriate to study the numerology associated with the number to possibly have a glimpse into what Nabokov might have been thinking when he picked those numbers.

First, to use numerology, you add together all of the numbers: 3+4+2=9. 9 is the number that signifies the sequence.

Adjectives associated with the number 9: hedonism, resentment, dejection, hostility, lack of integrity, prejudice, self-centeredness, and emotional volatility; hazy disposition, life as a drifter, an overly-detached disposition, confusion, impracticality, and submission.

This numerology article said, "9 has fleeting, vague impressions that vanish upon trying to weigh and analyze them. It's like the energy associated with the number 9 offers incredible insight, but at the same time it's telling you "sure, have a feel for it, but you're not allowed to scrutinize it too much." It's all right there for the 9, but it's not forever. Easy come, easy go, deep inspiration, broad visualizations, and unpredictability are key phrases for 9."

Perhaps the reason for the number 9 was to say that H.H. was blinded in his fantasy with Lolita, so as to not recognize that it could and would end. This was even more apparent after he got Room 342, when he finally met Quilty.

-Mr. McCoo, the man H.H. stayed with in the beginning of the novel, sounds like "My Cue", the biography Darkbloom wrote about Clare Quilty. Could that have been one of the Quilty references?