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.

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A102098 Triangular matrix, read by rows, that satisfies: T(n,k) = [T^3](n-1,k) when n>k>=0, with T(n,n) = (n+1).

Original entry on oeis.org

1, 1, 2, 7, 8, 3, 139, 152, 27, 4, 5711, 6200, 999, 64, 5, 408354, 442552, 69687, 3904, 125, 6, 45605881, 49399320, 7724835, 416704, 11375, 216, 7, 7390305396, 8003532512, 1248465852, 66464960, 1725875, 27432, 343, 8, 1647470410551
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2004

Keywords

Comments

Column 0 forms A082162. Column 1 forms A102099. Row sums form A102100. This triangle is a variant of A102086.

Examples

			Rows of T begin:
[1],
[1,2],
[7,8,3],
[139,152,27,4],
[5711,6200,999,64,5],
[408354,442552,69687,3904,125,6],
[45605881,49399320,7724835,416704,11375,216,7],
[7390305396,8003532512,1248465852,66464960,1725875,27432,343,8],...
Matrix cube T^3 equals T excluding the main diagonal:
[1],
[7,8],
[139,152,27],
[5711,6200,999,64],
[408354,442552,69687,3904,125],...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(A=matrix(1,1),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^3)[i-1,1], B[i,j]=(A^3)[i-1,j]));));A=B);return(A[n+1,k+1])}

Formula

T(n, 0) = A082162(n) for n>0, with T(0, 0) = 1.

A102099 Column 1 of triangular matrix A102098, which shifts upward to exclude the main diagonal under matrix cube.

Original entry on oeis.org

0, 2, 8, 152, 6200, 442552, 49399320, 8003532512, 1784040237288, 525504809786112, 198213959637435608, 93352856625931514024, 53776417402985961020144, 37244016639064540041311632
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2004

Keywords

Comments

Column 0 of A102098 is A082162.

Crossrefs

Programs

  • PARI
    {a(n)=local(A=matrix(2,2),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^3)[i-1,1], B[i,j]=(A^3)[i-1,j]));));A=B); return(A[n+1,2])}
Showing 1-2 of 2 results.