%I #19 Mar 12 2021 19:30:11
%S 1,1,20,1109,149777,40505320,19324787629,14885613436177,
%T 17346023517866756,29095672934852234945,67554301929824585326841,
%U 210353969049597164741983000,855886755812900060235077981449,4452236180954942685194928540509281
%N Number of permutations of 3 copies of 1..n avoiding adjacent step pattern up, up.
%H Mingjia Yang and Doron Zeilberger, <a href="https://arxiv.org/abs/1805.06077">Increasing Consecutive Patterns in Words</a>, arXiv:1805.06077 [math.CO], 2018.
%H Mingjia Yang, <a href="https://doi.org/10.7282/t3-d9z1-aw94">An experimental walk in patterns, partitions, and words</a>, Ph. D. Dissertation, Rutgers University (2020).
%Y Cf. A177605, A177615.
%K nonn
%O 0,3
%A _R. H. Hardin_, May 10 2010
%E a(10) from _Alois P. Heinz_, Oct 22 2013
%E a(0), a(11)-a(13) from _Alois P. Heinz_, Aug 08 2018