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A109960 Number triangle binomial(n+3k,4k). 4
1, 1, 1, 1, 5, 1, 1, 15, 9, 1, 1, 35, 45, 13, 1, 1, 70, 165, 91, 17, 1, 1, 126, 495, 455, 153, 21, 1, 1, 210, 1287, 1820, 969, 231, 25, 1, 1, 330, 3003, 6188, 4845, 1771, 325, 29, 1, 1, 495, 6435, 18564, 20349, 10626, 2925, 435, 33, 1, 1, 715, 12870, 50388, 74613, 53130 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Riordan array (1/(1-x), x/(1-x)^4). Rows sums are A055988. Diagonal sums are A109961. Inverse array is A109962.

LINKS

Table of n, a(n) for n=0..60.

FORMULA

Number triangle T(n, k)=binomial(n+3k, 4k)

EXAMPLE

Rows begin

1;

1,1;

1,5,1;

1,15,9,1;

1,35,45,13,1;

1,70,165,91,17,1;

CROSSREFS

Sequence in context: A157207 A008957 A136267 * A196019 A056940 A168288

Adjacent sequences:  A109957 A109958 A109959 * A109961 A109962 A109963

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry, Jul 06 2005

STATUS

approved

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Last modified February 15 22:28 EST 2019. Contains 320138 sequences. (Running on oeis4.)