A104446 Square of triangular matrix A104445, read by rows, where X=A104445 satisfies: SHIFT_LEFT_UP(X) = X^2 - X + I.
1, 2, 1, 3, 2, 1, 5, 5, 2, 1, 10, 13, 7, 2, 1, 25, 39, 25, 9, 2, 1, 78, 139, 100, 41, 11, 2, 1, 296, 587, 459, 205, 61, 13, 2, 1, 1330, 2897, 2418, 1149, 366, 85, 15, 2, 1, 6935, 16462, 14506, 7233, 2421, 595, 113, 17, 2, 1, 41352, 106301, 98161, 50905, 17706, 4535, 904
Offset: 0
Examples
Rows begin: 1; 2,1; 3,2,1; 5,5,2,1; 10,13,7,2,1; 25,39,25,9,2,1; 78,139,100,41,11,2,1; 296,587,459,205,61,13,2,1; 1330,2897,2418,1149,366,85,15,2,1 6935,16462,14506,7233,2421,595,113,17,2,1; ...
Programs
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PARI
T(n,k)=local(A=Mat(1),B);for(m=1,n,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+1,k+1])
Comments