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A274376 Number of modified skew Dyck paths such that the area between the x-axis and the path is n.

%I A274376 #9 Jun 19 2016 17:28:23
%S A274376 1,1,1,1,2,3,5,8,12,20,32,52,84,135,219,353,572,924,1495,2419,3912,
%T A274376 6331,10240,16570,26807,43374,70178,113546,183721,297258,480974,
%U A274376 778220,1259184,2037389,3296554,5333923,8630446,13964340,22594740,36559034,59153708,95712668
%N A274376 Number of modified skew Dyck paths such that the area between the x-axis and the path is n.
%C A274376 A modified skew Dyck path is a path in the first quadrant which begins at the origin, ends on the x-axis, consists of steps U=(1,1) (up), D=(1,-1) (down) and A=(-1,1) (anti-down) so that A and D steps do not overlap.
%F A274376 a(n) = Sum_{k=0..n} A274372(k,n).
%e A274376                /\    /\
%e A274376 a(5) = 3:   /\/  \  /  \/\  /\/\/\/\/\  .
%e A274376 .
%e A274376             /\
%e A274376             \ \    /\          /\          /\
%e A274376 a(6) = 5:   /  \  /  \/\/\  /\/  \/\  /\/\/  \  /\/\/\/\/\/\  .
%Y A274376 Column sums of A274372.
%Y A274376 Cf. A230823.
%K A274376 nonn
%O A274376 0,5
%A A274376 _Alois P. Heinz_, Jun 19 2016