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A122538
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Riordan array (1, x*f(x)) where f(x)is the g.f. of A006318.
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1
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1, 0, 1, 0, 2, 1, 0, 6, 4, 1, 0, 22, 16, 6, 1, 0, 90, 68, 30, 8, 1, 0, 394, 304, 146, 48, 10, 1, 0, 1806, 1412, 714, 264, 70, 12, 1, 0, 8558, 6752, 3534, 1408, 430, 96, 14, 1, 0, 41586, 33028, 17718, 7432, 2490, 652, 126, 16, 1
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| Triangle T(n,k), 0<=k<=n, read by rows, given by [0, 2, 1, 2, 1, 2, 1, ...] DELTA [1, 0, 0, 0, 0, 0, ...] where DELTA is the operator defined in A084938 . Inverse is Riordan array (1, x*(1-x)/(1+x)).
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FORMULA
| T(n,0)=0^n, T(n,k)=T(n-1,k-1)+T(n-1,k)+T(n,k+1)if k>0.
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EXAMPLE
| Triangle begins:
1;
0, 1:
0, 2, 1;
0, 6, 4, 1;
0, 22, 16, 6, 1;
0, 90, 68, 30, 8, 1;
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CROSSREFS
| Another version : A080247, A080245, A033877. Diagonals A000007, A006318, A006319, A006320, A006321 ; A000012, A005843, A054000 Cf. A001003 (row sums).
Sequence in context: A147720 A205813 A127631 * A090238 A047922 A021830
Adjacent sequences: A122535 A122536 A122537 * A122539 A122540 A122541
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KEYWORD
| nonn,tabl
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AUTHOR
| Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Sep 18 2006
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