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%I #6 Jun 13 2017 01:29:46
%S 1,2,5,13,39,139,587,2897,16462,106301,771313,6228073,55494336,
%T 541651873,5753940704,66147591142,818802488476,10864622564915,
%U 153914784829775,2319599022540318,37068215129072522,626279667948552452
%N Column 1 of triangular matrix A104446.
%C A104446 equals the square of triangular matrix A104445, read by rows, where X=A104445 satisfies: SHIFT_LEFT_UP(X) = X^2 - X + I.
%F a(n) = A091352(n-1) + A091353(n-1).
%o (PARI) a(n)=local(A=Mat(1),B);for(m=1,n+1,B=A^2-A+A^0; A=matrix(m+1,m+1);for(i=1,m+1, for(j=1,i, if(i<2 || j==i,A[i,j]=1,if(j==1,A[i,j]=1,A[i,j]=B[i-1,j-1]))))); return((A^2)[n+2,2])
%Y Cf. A104446, A091352, A091353.
%K nonn
%O 0,2
%A _Paul D. Hanna_, Mar 08 2005
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