Have you heard of Las Vegas? The 777 being the grand prize? Maybe it is not universal to all of western society but I have never before today heard of a culture where 3 was the lucky number. The USA’s culturally lucky number is absolutely 7.
I don't live in USA, the west includes Europe. 7 is maybe a lucky number in USA but not where I live. So I think that would be more of an American thing than a western thing maybe. Or maybe its related to some parts of Christianity but not others.
