Reminds me of the other property of 17: call a string of consecutive numbers (like 6,7,8,9) "stapled" if for any number in the string there is a mate in the string with which it has gcd > 1. Here 7 has no mate so 6,7,8,9 is not stapled. A stapled string of length n exists iff n >= 17. The string of length 17 starting at 2184 is the first one that exists. See A090318 for more information. Neil