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A110165 Riordan array (1/sqrt(1-6x+5x^2),(1-3x-sqrt(1-6x+5x^2))/(2x). 4
1, 3, 1, 11, 6, 1, 45, 30, 9, 1, 195, 144, 58, 12, 1, 873, 685, 330, 95, 15, 1, 3989, 3258, 1770, 630, 141, 18, 1, 18483, 15533, 9198, 3801, 1071, 196, 21, 1, 86515, 74280, 46928, 21672, 7210, 1680, 260, 24, 1, 408105, 356283, 236736, 119154, 44982, 12510 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Columns include A026375,A026376,A026377. Inverse is A110168. Rows sums are A110166. Diagonal sums are A110167.

LINKS

Table of n, a(n) for n=0..50.

FORMULA

Number triangle T(n, k)=sum{j=0..n, C(n, j)C(2j, j+k)}

T(n,0) = 3*T(n-1,0) + 2*T(n-1,1), T(n,k) = T(n-1,k-1) + 3*T(n-1,k) + T(n-1,k+1) for k>0, T(0,0) = 1, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Jan 24 2014

EXAMPLE

Rows begin

1;

3,1;

11,6,1;

45,30,9,1;

195,144,58,12,1;

873,685,330,95,15,1;

Production array begins:

3...1

2...3...1

0...1...3...1

0...0...1...3...1

0...0...0...1...3...1

0...0...0...0...1...3...1

0...0...0...0...0...1...3...1

... - Philippe Deléham, Feb 08 2014

CROSSREFS

Sequence in context: A027516 A092808 A113955 * A111965 A110440 A135574

Adjacent sequences:  A110162 A110163 A110164 * A110166 A110167 A110168

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Jul 14 2005

STATUS

approved

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Last modified January 23 02:34 EST 2019. Contains 319365 sequences. (Running on oeis4.)