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A059220
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The array in A059219 read by antidiagonals in 'up' direction.
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8
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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, 55, 0, 0, 239, 460, 680, 871, 1025, 1137, 1199, 6810, 6553, 6062, 5374, 4493, 3471, 2336, 1199, 0, 0, 6810, 13363, 19903, 25958, 31351, 35884, 39399, 41847
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table;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,4
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LINKS
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EXAMPLE
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The array begins
1 1 0 5 0 55 0 ...
0 1 3 5 48 55 ...
2 2 8 39 103 ...
0 12 27 152 ...
15 15 190 ...
0 221 ...
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MAPLE
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MATHEMATICA
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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 *)
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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