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A124376
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Number triangle with column k generated by x^k*(1+2kx+C(k,2)*x^2)/(1-x)^(k+1).
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0
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1, 1, 1, 1, 4, 1, 1, 7, 7, 1, 1, 10, 19, 10, 1, 1, 13, 37, 37, 13, 1, 1, 16, 61, 92, 61, 16, 1, 1, 19, 91, 185, 185, 91, 19, 1, 1, 22, 127, 326, 440, 326, 127, 22, 1, 1, 25, 169, 525, 896, 896, 525, 169, 25, 1, 1, 28, 217, 792
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OFFSET
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0,5
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COMMENTS
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LINKS
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FORMULA
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Number triangle T(n,k)=sum{j=0..n, C(k,k-j)*C(n-j,k)*C(2,j)}*[k<=n]
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EXAMPLE
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Triangle begins
1,
1, 1,
1, 4, 1,
1, 7, 7, 1,
1, 10, 19, 10, 1,
1, 13, 37, 37, 13, 1,
1, 16, 61, 92, 61, 16, 1,
1, 19, 91, 185, 185, 91, 19, 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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