A127832 - OEIS

%I #2 Mar 30 2012 18:57:10

%S 0,1,1,1,1,1,1,2,1,1,1,3,2,2,1,1,4,5,4,3,1,1,5,9,9,7,4,1,1,6,14,18,9,

%T 11,5,1,1,7,20,32,27,11,16,6,1,1,8,27,52,59,27,27,22,7,1,1,9,35,79,

%U 111,86,54,49,29,8,1,1,10,44,114,190,197,140,103,78,37,9,1,1,11,54,158,304,387

%N Array T by antidiagonals: for h>=0 and k>=0, T(h,k)=number of UR paths from (0,0) to (h,k) that touch the line y=2x/3 only at lattice points. A UR path is a path of steps of length 1 each directed up or right.

%e Northwest corner:

%e 0 1 1 1 1 1

%e 1 1 2 3 4 5

%e 1 1 2 5 9 14

%e 1 2 4 9 18 32

%e 1 3 7 9 27 59

%e The 4 UR paths for T(3,2) are RRRUU, RRURU, UURRR, URURR. These

%e paths touch the line y=2x/3 only at the lattice points (0,0) and (3,2).

%Y Cf. A047110, A127833.

%K nonn,tabl

%O 1,8

%A _Clark Kimberling_, Feb 01 2007