cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A114152 Triangle, read by rows, given by the product R^3*P^-1 using triangular matrices P=A113370, R=A113389.

Original entry on oeis.org

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

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Author

Paul D. Hanna, Nov 15 2005

Keywords

Comments

Complementary to A114153, which gives R^-1*P^3.

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

Cf. A113374 (P^2), A113370 (P), A113381 (Q), A113389 (R); A114150 (R^2*Q^-1=Q^3*P^-2), A114151 (R^-2*Q^3=Q^-1*P^2), A114153 (R^-1*P^3), A114154 (R^3*Q^-2), A114155 (Q^-2*P^3); A114156 (P^-1), A114158 (Q^-1), A114159 (R^-1).

Programs

  • 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]