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A159965 Riordan array (1/sqrt(1-4x), (1-2x-(1-3x)c(x))/(x*sqrt(1-4x))), c(x) the g.f. of A000108. 3
1, 2, 1, 6, 5, 1, 20, 21, 8, 1, 70, 84, 45, 11, 1, 252, 330, 220, 78, 14, 1, 924, 1287, 1001, 455, 120, 17, 1, 3432, 5005, 4368, 2380, 816, 171, 20, 1, 12870, 19448, 18564, 11628, 4845, 1330, 231, 23, 1, 48620, 75582, 77520, 54264, 26334, 8855, 2024, 300, 26, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Product of A007318 and A114422. Product of A007318^2 and A116382. Row sums are A108080.

Diagonal sums are A108081.

FORMULA

Number triangle T(n,k)=sum{j=0..n, C(n+k,j-k)*C(n,j)}.

EXAMPLE

Triangle begins

1,

2, 1,

6, 5, 1,

20, 21, 8, 1,

70, 84, 45, 11, 1,

252, 330, 220, 78, 14, 1,

924, 1287, 1001, 455, 120, 17, 1,

3432, 5005, 4368, 2380, 816, 171, 20, 1

CROSSREFS

Sequence in context: A008970 A055896 A193723 * A116395 A159924 A133367

Adjacent sequences:  A159962 A159963 A159964 * A159966 A159967 A159968

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Apr 28 2009

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Last modified February 15 10:52 EST 2012. Contains 205763 sequences.