%I A115513
%S A115513 1,1,1,0,0,1,0,0,0,1,1,1,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,1,0,0,0,0,
               1,0,0,0,0,0,
%T A115513 0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
               0,1,0,0,0,0,0,
%U A115513 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
%V A115513 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,
               0,0,1,0,0,0,0,0,
%W A115513 0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,-1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,
               0,0,1,0,0,0,0,0,
%X A115513 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 A115513 Inverse of matrix (1,x)+(x,x^3).
%C A115513 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 A115513 Triangle begins
%e A115513 1,
%e A115513 -1, 1,
%e A115513 0, 0, 1,
%e A115513 0, 0, 0, 1,
%e A115513 1, -1, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, -1, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
%e A115513 -1, 1, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 1,
%e A115513 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
%Y A115513 Sequence in context: A128190 A128189 A115512 this_sequence A133080 A010815 
               A080995
%Y A115513 Adjacent sequences: A115510 A115511 A115512 this_sequence A115514 A115515 
               A115516
%K A115513 sign,tabl
%O A115513 0,1
%A A115513 Paul Barry (pbarry(AT)wit.ie), Jan 23 2006