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Search: id:A117352
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| A117352 |
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Riordan array (1/(1-2x), x(1-2x)/(1-x)). |
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+0
3
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| 1, 2, 1, 4, 1, 1, 8, 1, 0, 1, 16, 1, -1, -1, 1, 32, 1, -2, -2, -2, 1, 64, 1, -3, -2, -2, -3, 1, 128, 1, -4, -1, 0, -1, -4, 1, 256, 1, -5, 1, 3, 3, 1, -5, 1, 512, 1, -6, 4, 6, 6, 6, 4, -6, 1, 1024, 1, -7, 8, 8, 6, 6, 8, 8, -7, 1
(list; table; graph; listen)
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OFFSET
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0,2
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COMMENT
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Row sums are A038505. Diagonal sums are A117353. Inverse is A117354.
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FORMULA
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Number triangle T(n,k)=sum{j=0..n-k, C(j-k,j)C(n-k,j)}
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EXAMPLE
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Triangle begins
1,
2, 1,
4, 1, 1,
8, 1, 0, 1,
16, 1, -1, -1, 1,
32, 1, -2, -2, -2, 1,
64, 1, -3, -2, -2, -3, 1
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CROSSREFS
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Sequence in context: A137633 A066633 A088443 this_sequence A137710 A068009 A140168
Adjacent sequences: A117349 A117350 A117351 this_sequence A117353 A117354 A117355
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KEYWORD
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easy,sign,tabl
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AUTHOR
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Paul Barry (pbarry(AT)wit.ie), Mar 09 2006
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