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A119335
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Number triangle T(n,k)=sum{j=0..n-k, C(k,3j)C(n-k,3j)}.
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5
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 5, 5, 1, 1, 1, 1, 1, 1, 11, 17, 11, 1, 1, 1, 1, 1, 1, 21, 41, 41, 21, 1, 1, 1, 1, 1, 1, 36, 81, 101, 81, 36, 1, 1, 1
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,25
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COMMENTS
| Row sums are A119336. Product of Pascal's triangle and A119337.
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FORMULA
| Column k has g.f. (x^k/(1-x))*sum{j=0..k, C(k,3j)(x/(1-x))^(3j)}
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EXAMPLE
| Triangle begins
1,
1, 1,
1, 1, 1,
1, 1, 1, 1,
1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1,
1, 1, 1, 2, 1, 1, 1,
1, 1, 1, 5, 5, 1, 1, 1,
1, 1, 1, 11, 17, 11, 1, 1, 1,
1, 1, 1, 21, 41, 41, 21, 1, 1, 1,
1, 1, 1, 36, 81, 101, 81, 36, 1, 1, 1
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CROSSREFS
| Cf. A119326.
Sequence in context: A082907 A146532 A184879 * A155869 A176564 A154338
Adjacent sequences: A119332 A119333 A119334 * A119336 A119337 A119338
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KEYWORD
| easy,nonn,tabl
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), May 14 2006
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