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Search: id:A113955
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| A113955 |
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Riordan array (1/((1-4x)c(x)),xc(x)/sqrt(1-4x)), c(x) the g.f. of A000108. |
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+0
2
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| 1, 3, 1, 11, 6, 1, 42, 30, 9, 1, 163, 140, 58, 12, 1, 638, 630, 325, 95, 15, 1, 2510, 2772, 1686, 624, 141, 18, 1, 9908, 12012, 8330, 3682, 1064, 196, 21, 1, 39203, 51480, 39796, 20264, 7050, 1672, 260, 24, 1, 155382, 218790, 185517, 106203, 42849, 12303, 2475
(list; table; graph; listen)
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OFFSET
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0,2
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COMMENT
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Columns include A032443,A002457,A018218,A038836. Row sums are A100192. Diagonal sums are A113956.
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FORMULA
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Riordan array ((1/(1-4x)+1/sqrt(1-4x))/2, (2x/((1-4x)+sqrt(1-4x)))); Number triangle T(n, k)=sum{j=0..n, C(j, j-k)C(2n, n-j)}.
T(n,k)=sum{j=0..n, C(2n,j)C(n-j,k)}; - Paul Barry (pbarry(AT)wit.ie), Apr 03 2006
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EXAMPLE
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Triangle begins
1;
3, 1;
11, 6, 1;
42, 30, 9, 1;
163, 140, 58, 12, 1;
638, 630, 325, 95, 15, 1;
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CROSSREFS
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Sequence in context: A027446 A027516 A092808 this_sequence A110165 A111965 A110440
Adjacent sequences: A113952 A113953 A113954 this_sequence A113956 A113957 A113958
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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), Nov 09 2005
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