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 A181650 Inverse of number triangle A070909. 2

%I

%S 1,-1,1,-1,0,1,0,0,-1,1,0,0,-1,0,1,0,0,0,0,-1,1,0,0,0,0,-1,0,1,0,0,0,

%T 0,0,0,-1,1,0,0,0,0,0,0,-1,0,1,0,0,0,0,0,0,0,0,-1,1,0,0,0,0,0,0,0,0,

%U -1,0,1

%N Inverse of number triangle A070909.

%C Generalized (conditional) Riordan array with k-th column generated by If(mod(k,2)=0,x^k*(1-x-x^2),x^k).

%C Triangle T(n,k), read by rows, given by (-1,2,-1/2,-1/2,0,0,0,0,0,0,0,...) DELTA (1,0,-1,0,0,0,0,0,0,0,0,0,...) where DELTA is the operator defined in A084938. - From Philippe Deléham, Nov 19 2011.

%F G.f.: (1+(y-1)*x-x^2)/((1-y*x)*(1+y*x)).- From Philippe Deléham, Nov 19 2011.

%e Triangle begins

%e 1,

%e -1, 1,

%e -1, 0, 1,

%e 0, 0, -1, 1,

%e 0, 0, -1, 0, 1,

%e 0, 0, 0, 0, -1, 1,

%e 0, 0, 0, 0, -1, 0, 1,

%e 0, 0, 0, 0, 0, 0, -1, 1,

%e 0, 0, 0, 0, 0, 0, -1, 0, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, -1, 1,

%e 0, 0, 0, 0, 0, 0, 0, 0, -1, 0, 1

%e Production matrix begins

%e -1, 1,

%e -2, 1, 1,

%e -1, 1, -1, 1,

%e -1, 1, -2, 1, 1,

%e -1, 1, -1, 1, -1, 1,

%e -1, 1, -1, 1, -2, 1, 1,

%e -1, 1, -1, 1, -1, 1, -1, 1,

%e -1, 1, -1, 1, -1, 1, -2, 1, 1,

%e -1, 1, -1, 1, -1, 1, -1, 1, -1, 1

%Y Cf. A084221, A084938

%K easy,sign,tabl

%O 0,1

%A _Paul Barry_, Nov 03 2010

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Last modified May 25 10:17 EDT 2013. Contains 225647 sequences.