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A117362 Riordan array (1-2x,x(1-x)). 1
1, -2, 1, 0, -3, 1, 0, 2, -4, 1, 0, 0, 5, -5, 1, 0, 0, -2, 9, -6, 1, 0, 0, 0, -7, 14, -7, 1, 0, 0, 0, 2, -16, 20, -8, 1, 0, 0, 0, 0, 9, -30, 27, -9, 1, 0, 0, 0, 0, -2, 25, -50, 35, -10, 1, 0, 0, 0, 0, 0, -11, 55, -77, 44, -11, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
A signed version of A113214. Inverse of A092392. Row sums are A100051(n+1) with g.f. (1-2x)/(1-x+x^2). Diagonal sums are A117363.
LINKS
FORMULA
Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+2*C(k, n-k-1))
EXAMPLE
Triangle begins
1,
-2, 1,
0, -3, 1,
0, 2, -4, 1,
0, 0, 5, -5, 1,
0, 0, -2, 9, -6, 1,
0, 0, 0, -7, 14, -7, 1,
0, 0, 0, 2, -16, 20, -8, 1
CROSSREFS
Sequence in context: A130055 A202452 A127013 * A247492 A113214 A280494
KEYWORD
easy,sign,tabl
AUTHOR
Paul Barry, Mar 10 2006
STATUS
approved

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Last modified March 28 10:55 EDT 2024. Contains 371241 sequences. (Running on oeis4.)