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Search: id:A124376
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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
1
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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
(list; table; graph; listen)
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OFFSET
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0,5
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COMMENT
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Columns include A016777,A003215,A096000. T(n,k)=T(n-k,k).
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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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Sequence in context: A152236 A157172 A131060 this_sequence A047671 A081577 A146986
Adjacent sequences: A124373 A124374 A124375 this_sequence A124377 A124378 A124379
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KEYWORD
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easy,nonn,tabl
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AUTHOR
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Paul Barry (pbarry(AT)wit.ie), Oct 28 2006
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