This is a lot like what the elevator in the apartment building I grew up in looked like. Did you notice something? That's right, there's no 13th floor. Actually, technically the 14th floor is the 13th, but because of the superstition that 13 is an unlucky number (Triskaidekaphobia), many New York City buildings have omitted a thirteenth floor. However, 13 is also a good number depending on the culture you're from or are part of. For instance, in Judaism, 13 is a holy number. See Maimonides The 13 principles of faith and Thirteen Attributes of Mercy on Wikipedia, the free encyclopaedia.
"Many Christians have long believed that Friday was unlucky because it was the day of the week when Jesus was crucified. The number 13 was believed to bring bad luck because there were 13 people at The Last Supper. Since there were 12 tribes of Israel, that number was considered lucky." Friday the 13th — Infoplease.com
"The number 13, especially Friday the 13th, has long been considered lucky in Judaism, and some think that the general population's fear of 13 stems from anti-semitism." 13 (number) - Wikipedia
"The number 13 could also have been considered pagan because there are 13 months in the pagan lunar calendar. The lunar calendar also corresponds to the human menstrual cycle, connecting the number to femininity." How Friday the 13th Works by Tom Harris - How Stuff Works
"It is believed that the fear for the number 13 stems from primitive man being unable to count past 12." List of phobias Friday, lucky or not - Didyouknow.org