Which is kind of surprising. Unlucky numbers often come up in software engineering when initializing psuedo-random generators. For example using an unlucky number with the C srand() function will more quickly expose bugs due to sloppy or lazy programming than using a lucky number would. Another area where unlucky numbers predominate is when gambling with some one else’s money whom you don’t like. It’s one thing to get lucky with borrowed money but quite another when that money is borrowed from some one you don’t like or who is always bragging about how lucky the are.
And no you can’t always just assume 13 will always be unlucky. It’s much better to have a couple extra options for picking unlucky numbers.
So to start with it seems like if you take one person’s lucky number and then add another person’s lucky number and then divide the sum by two that the result is generally unlucky. Unless both of the people you ask give you the same lucky number in which case keep asking people until you get a different number and then divide by the number of people you had to ask. This approach is sometimes difficult because there are some people out there who become suspicious about your motives if you are asking them about their lucky numbers. In some cases a lifeflong lucky number can be a deeply personal bit of information.
Another option for unlucky numbers is to compute them as the inverse of lucky numbers. For example if 117 is lucky and has won the lottery four times in a given month then you could take the maximum possible value minus the lucky number to get the unlucky number. So in this case it would be 999-117 or 882. Computing unlucky numbers this is way is one of the easiest ways because you can just read the luckiest or most winning numbers from the last month of lottery tickets and calculate the unlucky numbers directly.
Lastly you can pick unlucky numbers by keeping a list of your losing lottery numbers and keeping track of which number has been played the most and won the least. This method can get expensive though so I would recommend either of the previous two techniques before paying for unlucky numbers.
imogen heap (Clear the Area), Great Northern (Into the sun), Malajube (St. Fortunat) “j’ai jamais su remonter le moral, je t’en prie mon ami tiens bon”