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A113139 Number triangle, equal to half of Delannoy square array A008288. 3
1, 3, 1, 13, 5, 1, 63, 25, 7, 1, 321, 129, 41, 9, 1, 1683, 681, 231, 61, 11, 1, 8989, 3653, 1289, 377, 85, 13, 1, 48639, 19825, 7183, 2241, 575, 113, 15, 1, 265729, 108545, 40081, 13073, 3649, 833, 145, 17, 1, 1462563, 598417, 224143, 75517, 22363, 5641 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Row sums are A047781(n+1). Diagonal sums are A113140. Inverse is A113141.

FORMULA

T(n, k)=sum{j=0..n, C(n-k, j)C(n+j, k+j)}; T(n, k)=sum{j=0..n, C(n, j)C(n-k, j-k)2^(n-j)};

EXAMPLE

Triangle begins

1;

3, 1;

13, 5, 1;

63, 25, 7, 1;

321, 129, 41, 9, 1;

1683,681, 231, 61, 11, 1;

8989,3653,1289,377,85, 13, 1;

CROSSREFS

Sequence in context: A016479 A170910 A134768 * A143411 A096773 A118384

Adjacent sequences:  A113136 A113137 A113138 * A113140 A113141 A113142

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Oct 15 2005

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Last modified February 14 22:03 EST 2012. Contains 205668 sequences.