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A119329
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Number triangle T(n,k)=sum{j=0..n-k, C(k,2j)C(n-k,2j)*2^j}.
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2
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 7, 7, 1, 1, 1, 1, 13, 19, 13, 1, 1, 1, 1, 21, 37, 37, 21, 1, 1, 1, 1, 31, 61, 77, 61, 31, 1, 1, 1, 1, 43, 91, 141, 141, 91, 43, 1, 1, 1, 1, 57, 127, 241, 301, 241, 127, 57, 1, 1
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OFFSET
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0,13
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COMMENTS
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LINKS
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FORMULA
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Column k has g.f. (x^k/(1-x))*sum{j=0..k, C(k,2j)*2^j*(x/(1-x))^(2j)}
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EXAMPLE
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Triangle begins
1,
1, 1,
1, 1, 1,
1, 1, 1, 1,
1, 1, 3, 1, 1,
1, 1, 7, 7, 1, 1,
1, 1, 13, 19, 13, 1, 1,
1, 1, 21, 37, 37, 21, 1, 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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