A114152 Triangle, read by rows, given by the product R^3*P^-1 using triangular matrices P=A113370, R=A113389.
1, 8, 1, 84, 14, 1, 1296, 252, 20, 1, 27850, 5957, 510, 26, 1, 784146, 179270, 16180, 858, 32, 1, 27630378, 6641502, 623115, 34125, 1296, 38, 1, 1177691946, 294524076, 28470525, 1599091, 61952, 1824, 44, 1
Offset: 0
Examples
Triangular matrix R^3*P^-1 begins: 1; 8,1; 84,14,1; 1296,252,20,1; 27850,5957,510,26,1; 784146,179270,16180,858,32,1; 27630378,6641502,623115,34125,1296,38,1; ... Compare to P^2 (A113374): 1; 2,1; 6,8,1; 37,84,14,1; 429,1296,252,20,1; 7629,27850,5957,510,26,1; ... Thus R^3*P^-1 equals P^2 shift left one column.
Crossrefs
Programs
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PARI
T(n,k)=local(P,Q,R,W);P=Mat(1);for(m=2,n+1,W=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,W[i,j]=1,if(j==1, W[i,1]=1,W[i,j]=(P^(3*j-2))[i-j+1,1]));));P=W); Q=matrix(#P,#P,r,c,if(r>=c,(P^(3*c-1))[r-c+1,1])); R=matrix(#P,#P,r,c,if(r>=c,(P^(3*c))[r-c+1,1])); (R^3*P^-1)[n+1,k+1]
Comments