No idea. I couldn't find the sequence in the OP at
but swapping the commas for spaces they all showed up in only one sequence http://www.research.att.com/~njas/se...lish&go=Search
and there were 2,5,8,11 numbers between them. 2,5,8,11 shows up in 65 sequences and has varying numbers after it, but 14 seems common. So this leads to my guess of 6121.