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A127574
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Triangle T(n,k) = k*sigma(n) if k divides n, else 0.
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1
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1, 3, 6, 4, 0, 12, 7, 14, 0, 28, 6, 0, 0, 0, 30, 12, 24, 36, 0, 0, 72, 8, 0, 0, 0, 0, 0, 56, 15, 30, 0, 60, 0, 0, 0, 120, 13, 0, 39, 0, 0, 0, 0, 0, 117, 18, 36, 0, 0, 90, 0, 0, 0, 0, 180, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 132, 28, 56, 84, 112, 0, 168, 0, 0, 0, 0, 0, 336
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OFFSET
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1,2
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LINKS
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FORMULA
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T(n,k) = Sum_{j=k..n} A130208(n,j)*A127093(j,k), product of the two infinite lower triangular matrices.
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EXAMPLE
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First few rows of the triangle are:
1;
3, 6;
4, 0, 12;
7, 14, 0, 28;
6, 0, 0, 0, 30;
12, 24, 36, 0, 0, 72;
...
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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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