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A133112
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Triangular array, read by rows, associated with sums of certain Vandermonde determinants.
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5
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1, 2, 1, 3, 4, 1, 4, 10, 8, 1, 5, 20, 35, 16, 1, 6, 35, 112, 126, 32, 1, 7, 56, 294, 672, 462, 64, 1, 8, 84, 672, 2772, 4224, 1716, 128, 1, 9, 120, 1386, 9504, 28314, 27456, 6435, 256, 1, 10, 165, 2640, 28314, 151008, 306735, 183040, 24310, 512, 1
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OFFSET
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1,2
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COMMENTS
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Appears to be the same as A073165 read as a triangular array (excluding the first column).
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LINKS
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FORMULA
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T(n,k)=1/(1!*2! ... *k!)*sum {1 <= x_1, ...,x_k <= n}|det V(x_1, ...,x_k)|, where V(x_1, ...,x_k} is the Vandermonde matrix of order k. For example, T(n,2) = 1/2*sum {1<=i,j<= n} |i-j|. T(n,k) = 1/(1!*2! ... *k!)*sum {1 <= x_1, ...,x_k <= n} |(product {1 <= i < j <= k} (x_j - x_i) )|.
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EXAMPLE
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Triangle starts
1;
2 1;
3 4 1;
4 10 8 1;
5 20 35 16 1;
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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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