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A059220 The array in A059219 read by antidiagonals in 'up' direction.

%I A059220 #15 Dec 31 2016 01:04:38
%S A059220 1,0,1,2,1,0,0,2,3,5,15,12,8,5,0,0,15,27,39,48,55,239,221,190,152,103,
%T A059220 55,0,0,239,460,680,871,1025,1137,1199,6810,6553,6062,5374,4493,3471,
%U A059220 2336,1199,0,0,6810,13363,19903,25958,31351,35884,39399,41847
%N A059220 The array in A059219 read by antidiagonals in 'up' direction.
%H A059220 G. C. Greubel, <a href="/A059220/b059220.txt">Table of n, a(n) for the first 50 rows, flattened</a>
%H A059220 <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a>
%e A059220 The array begins
%e A059220    1   1   0   5   0  55   0 ...
%e A059220    0   1   3   5  48  55   ...
%e A059220    2   2   8  39 103  ...
%e A059220    0  12  27 152 ...
%e A059220   15  15 190 ...
%e A059220    0 221 ...
%p A059220 See A059219 for Maple code.
%t A059220 max = 9; t[0, 0] = 1; t[0, _?EvenQ] = 0; t[_?OddQ, 0] = 0; t[n_, k_] /; OddQ[n + k] (* up *) := t[n, k] = t[n+1, k-1] + Sum[t[n, j], {j, 0, k-1}]; t[n_, k_] /; EvenQ[n + k] (* down *) := t[n, k] = t[n-1, k+1] + Sum[t[j, k], {j, 0, n-1}]; Table[t[n - k, k], {n, 0, max}, {k, 0, n}] // Flatten (* _Jean-François Alcover_, Aug 19 2013 *)
%Y A059220 Cf. A000667, A059216, A059219, A059217, A059235.
%K A059220 easy,nonn,tabl,nice
%O A059220 1,4
%A A059220 _N. J. A. Sloane_, Jan 18 2001
%E A059220 More terms from _Floor van Lamoen_, Jan 19 2001