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A253587
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The sum of the i-th ternary digits of n, k, and T(n,k) equals 0 (mod 3) for each i>=0 (leading zeros included); triangle T(n,k), n>=0, 0<=k<=n, read by rows.
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4
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0, 2, 1, 1, 0, 2, 6, 8, 7, 3, 8, 7, 6, 5, 4, 7, 6, 8, 4, 3, 5, 3, 5, 4, 0, 2, 1, 6, 5, 4, 3, 2, 1, 0, 8, 7, 4, 3, 5, 1, 0, 2, 7, 6, 8, 18, 20, 19, 24, 26, 25, 21, 23, 22, 9, 20, 19, 18, 26, 25, 24, 23, 22, 21, 11, 10, 19, 18, 20, 25, 24, 26, 22, 21, 23, 10, 9, 11
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OFFSET
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0,2
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LINKS
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FORMULA
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T(n,k) = T(floor(n/3),floor(k/3))*3+(6-(n mod 3)-(k mod 3) mod 3), T(0,0) = 0.
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EXAMPLE
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Triangle T(n,k) begins:
0;
2, 1;
1, 0, 2;
6, 8, 7, 3;
8, 7, 6, 5, 4;
7, 6, 8, 4, 3, 5;
3, 5, 4, 0, 2, 1, 6;
5, 4, 3, 2, 1, 0, 8, 7;
4, 3, 5, 1, 0, 2, 7, 6, 8;
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MAPLE
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T:= proc(n, k) local i, j; `if`(n=0 and k=0, 0,
T(iquo(n, 3, 'i'), iquo(k, 3, 'j'))*3 +irem(6-i-j, 3))
end:
seq(seq(T(n, k), k=0..n), n=0..14);
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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