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A115513 Inverse of matrix (1,x)+(x,x^3). 1

%I #4 Oct 30 2022 21:20:56

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

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

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

%N Inverse of matrix (1,x)+(x,x^3).

%C Row sums are A014578(n+5) or sum{k=0..ceiling(log(n+4)/log(3)),(-1)^k*(floor((n+4)/3^k)-floor((n+3)/3^k)}. Inverse of number triangle A115512.

%e Triangle begins

%e 1,

%e -1, 1,

%e 0, 0, 1,

%e 0, 0, 0, 1,

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

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

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

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

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

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

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

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

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

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

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

%Y Cf. A014578, A115512.

%K sign,tabl

%O 0,1

%A _Paul Barry_, Jan 23 2006

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Last modified April 23 06:04 EDT 2024. Contains 371906 sequences. (Running on oeis4.)