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 A098599 Riordan array ((1+2x)/(1+x),(1+x)). 7

%I

%S 1,1,1,-1,2,1,1,0,3,1,-1,0,2,4,1,1,0,0,5,5,1,-1,0,0,2,9,6,1,1,0,0,0,7,

%T 14,7,1,-1,0,0,0,2,16,20,8,1,1,0,0,0,0,9,30,27,9,1,-1,0,0,0,0,2,25,50,

%U 35,10,1,1,0,0,0,0,0,11,55,77,44,11,1,-1,0,0,0,0,0,2,36,105,112,54,12,1,1,0,0,0,0,0,0,13,91,182,156,65,13,1,-1,0,0,0,0

%N Riordan array ((1+2x)/(1+x),(1+x)).

%F Triangle T(n, k) = binomial(k, n-k)+binomial(k-1, n-k-1).

%F T(n,k) = T(n-1,k-1)-T(n-1,k)+2*T(n-2,k-1)+T(n-3,k-1), T(0,0)=1, T(1,0)=1, T(1,1)=1, T(n,k)=0 if k<0 or if k>n. - _Philippe DelĂ©ham_, Jan 09 2014

%e Rows begin {1}, {1,1}, {-1,2,1}, {1,0,3,1}, {-1,0,2,4,1},...

%Y Row sums are A098600. Diagonal sums are A098601.

%Y Cf. A029635. Apart from signs, same as A100218. Very similar to triangle A111125.

%K easy,sign,tabl

%O 0,5

%A _Paul Barry_, Sep 17 2004

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Last modified October 21 01:18 EDT 2019. Contains 328291 sequences. (Running on oeis4.)