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A117377 Riordan array (1-4x,x(1-x)). 3
1, -4, 1, 0, -5, 1, 0, 4, -6, 1, 0, 0, 9, -7, 1, 0, 0, -4, 15, -8, 1, 0, 0, 0, -13, 22, -9, 1, 0, 0, 0, 4, -28, 30, -10, 1, 0, 0, 0, 0, 17, -50, 39, -11, 1, 0, 0, 0, 0, -4, 45, -80, 49, -12, 1, 0, 0, 0, 0, 0, -21, 95, -119, 60, -13, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums are A117378. Diagonal sums are A117379. Inverse is A117380.

LINKS

Table of n, a(n) for n=0..65.

FORMULA

Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+4*C(k, n-k-1))

EXAMPLE

Triangle begins

1,

-4, 1,

0, -5, 1,

0, 4, -6, 1,

0, 0, 9, -7, 1,

0, 0, -4, 15, -8, 1,

0, 0, 0, -13, 22, -9, 1,

0, 0, 0, 4, -28, 30, -10, 1

CROSSREFS

Sequence in context: A126217 A303499 A108944 * A046784 A011349 A303126

Adjacent sequences:  A117374 A117375 A117376 * A117378 A117379 A117380

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, Mar 10 2006

STATUS

approved

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Last modified February 18 05:40 EST 2019. Contains 320245 sequences. (Running on oeis4.)