(In reply to
Answer?? by Raika)
That sounds like the most logical sequence I could find. The sequence found by cheating in the Online Encyclopedia of Integer Sequences has an explanation that I can't understand at all.
As for your solution, perhaps a better explanation is:
The odd terms go in the sequence 1,2,3,4, 4,5,6,7, 7,8,9,10, 10,11,12,13, ... (every fourth term in the counting sequence repeated). The even terms reiterate the whole sequencethat is term 2n = term n.

Posted by Charlie
on 20050526 18:41:43 