13 - Unlucky for Some?

I was recently reminded that some people take the "unluckiness" of the number 13 very seriously, when the lift in the Washington hotel I was staying in apparently skipped from the 12th to the 14th floor. This is a phenomenon not confined to the USA, but often causes a great deal of mirth from less suspicious travellers.

Superstitions around the number 13 are entrenched in a number of cultures, and Agatha Christie acknowledged this in 3 titles (as far as I know - but were there more?)

THIRTEEN FOR LUCK
A republication "for younger readers" of 13 short stories, all of them previously published in the US, UK, or both.
The stories are  
Accident (from The Listerdale Mystery);  
The Bird with the Broken Wing and  
The Face of Helen (from The Mysterious Mr. Quin);  
The Blue Geranium and  
The Four Suspects (from The Thirteen Problems);
The Girdle of Hippolyta and  
The Nemean Lion (The Labours of Hercules);  
The Market Basing Mystery (The Under Dog);
Problem at Pollensa Bay and  
The Regatta Mystery (The Regatta Mystery);  
The Tape-Measure Murder (Three Blind Mice);  
The Unbreakable Alibi (Partners in Crime); and  
The Veiled Lady (Poirot's Early Cases).
They are taken variously from 9 different books and include 4 Poirot stories, 3 Miss Marple stories, 1 of Tommy & Tuppence, 2 of Parker Pyne, and 2 of Mr. Quin.

In THIRTEEN AT DINNER (aka LORD EDGWARE DIES) Agatha Christie worked on a superstition that sitting 13 people at a table will result in the death of one member.

This was a good solid Christie read (as you'll see from my review) although Hercules Poirot always regarded the case as one of his failures.

Coincidentally it was also Christie's 13th novel

THE THIRTEEN PROBLEMS, reviewed here, saw the debut of Miss Marple.

It consists of 13 short stories, all dedicated to demonstrating the cleverness of Miss Marple, who mainly solves the mysteries by comparing them to her observations of life in St. Mary Mead.

Other authors have similarly used the number 13 in their titles.
Perhaps you'd like to comment on your favourite.