%I #4 Sep 11 2015 18:47:33
%S 1,1,3,57,778,47673,1477381,196352061,10896848134,2539183745028,
%T 220995092995233,79875004816604671,10032237471596350240,
%U 5198811549997063847059,890008776794671492878641,626002734896306246681963237,140112228518254335504033414806
%N Number of permutations p of [2n] such that the up-down signature of p has nonnegative partial sums with a maximal value of n.
%H Alois P. Heinz, <a href="/A262127/b262127.txt">Table of n, a(n) for n = 0..50</a>
%F a(n) = A262125(2n,n).
%Y Cf. A262125.
%K nonn
%O 0,3
%A _Alois P. Heinz_, Sep 11 2015