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Search: id:A124234
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| A124234 |
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Riordan array (1/(1-x), x(1+x)^2). |
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+0 1
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| 1, 1, 1, 1, 3, 1, 1, 4, 5, 1, 1, 4, 11, 7, 1, 1, 4, 15, 22, 9, 1, 1, 4, 16, 42, 37, 11, 1, 1, 4, 16, 57, 93, 56, 13, 1, 1, 4, 16, 63, 163, 176, 79, 15, 1, 1, 4, 16, 64, 219, 386, 299, 106
(list; table; graph; listen)
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OFFSET
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0,5
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COMMENT
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Row sums are A077864. Diagonal sums are A004695(n+3). T(2n,n) is A032443.
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FORMULA
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Number triangle T(n,k)=sum{j=0..n-k, C(2k,j)}
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EXAMPLE
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Triangle begins
1,
1, 1,
1, 3, 1,
1, 4, 5, 1,
1, 4, 11, 7, 1,
1, 4, 15, 22, 9, 1,
1, 4, 16, 42, 37, 11, 1
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CROSSREFS
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Sequence in context: A102716 A134510 A124020 this_sequence A135226 A104730 A131238
Adjacent sequences: A124231 A124232 A124233 this_sequence A124235 A124236 A124237
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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 22 2006
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