156716

I worked systematically and used trial and error and I found that you couldn't put n consecutive numbers in one sequence. I also found that the higher the value of pair, the less available positions the pair could be. Using this knowledge, I found 2 solutions for 1's, 2's and 3's, 312132 and 231213.I found 2 solutions for 1's, 2's, 3's and 4's, 41312432 and 23421314. I couldn't find any for 5's or sixes.I found two for 7's, 15173465324726 and 71316435724625.