A006220 - OEIS

%I M2866 #11 Feb 03 2017 17:12:20

%S 1,1,3,10,45,251,1638,12300,104877,1000135,10534062,121436206,

%T 1521332904

%N From descending subsequences of permutations.

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H S. Pilpel, <a href="http://dx.doi.org/10.1016/0097-3165(90)90022-O">Descending subsequences of random permutations</a>, J. Combin. Theory, A 53 (1990), 96-116.

%Y Diagonal of A224652.

%K nonn,more

%O 1,3

%A _N. J. A. Sloane_.

%E a(11)-a(13) from _Sean A. Irvine_, Feb 03 2017