%I #18 Mar 12 2021 19:29:28
%S 1,1,6,90,2401,101761,6291216,534649500,59805912601,8519381695801,
%T 1505829663622626,323403835613234310,82950935886564603001,
%U 25045332571083387933241,8792814340394735774002236,3551704765357254157594658520,1635557840926288462033032891601
%N Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, 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. A177564, A177574, A177594.
%K nonn
%O 0,3
%A _R. H. Hardin_, May 10 2010
%E a(12)-a(15) from _Alois P. Heinz_, Nov 01 2013
%E a(0), a(16) from _Alois P. Heinz_, Aug 08 2018