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Inverse of matrix (1,x)+(x,x^2) (expressed in Riordan array notation).
2

%I #3 Mar 30 2012 18:59:13

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

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

%U 0,0,1,0,0,-1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,-1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,-1,0,1

%N Inverse of matrix (1,x)+(x,x^2) (expressed in Riordan array notation).

%C Row sums are A035263 (first Feigenbaum symbolic (or period-doubling) sequence). Columns are signed stretched Fredholm-Rueppel sequences. Inverse is A115356.

%F Number triangle whose k-th column has g.f. x^k*sum{j>=0, (-1)^j*(x^(2j-1))^(k+1)}.

%e Triangle begins

%e 1;

%e -1, 1;

%e 0, 0, 1;

%e 1, -1, 0, 1;

%e 0, 0, 0, 0, 1;

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

%e 0, 0, 0, 0, 0, 0, 1;

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

%e 0, 0, 0, 0, 0, 0, 0, 0, 1;

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

%e 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;

%K easy,sign,tabl

%O 0,1

%A _Paul Barry_, Jan 21 2006