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.

Showing 1-4 of 4 results.

A113355 Triangle T, read by rows, equal to the matrix square of triangle A113350, where T transforms column k of T into column k+1 of T.

Original entry on oeis.org

1, 4, 1, 18, 8, 1, 112, 68, 12, 1, 965, 712, 150, 16, 1, 10957, 9270, 2184, 264, 20, 1, 156699, 147174, 37523, 4912, 410, 24, 1, 2727793, 2786270, 754171, 104476, 9280, 588, 28, 1, 56306695, 61662544, 17502145, 2531004, 235025, 15672, 798, 32, 1
Offset: 0

Views

Author

Paul D. Hanna, Nov 08 2005

Keywords

Comments

Also, T transforms column k of A113340^2 into column k+1 of A113340^2. Column 0: T(n,0) = A113356(n) = A113346(n+1) - 1, where A113346 equals column 0 of triangle A113345 (=A113340^2).

Examples

			Triangle T begins:
1;
4,1;
18,8,1;
112,68,12,1;
965,712,150,16,1;
10957,9270,2184,264,20,1;
156699,147174,37523,4912,410,24,1;
2727793,2786270,754171,104476,9280,588,28,1;
56306695,61662544,17502145,2531004,235025,15672,798,32,1; ...
where T transforms column k of T into column k+1:
at k=0, [Q^2]*[1,4,18,112,965,...] = [1,8,68,712,9270,...];
at k=1, [Q^2]*[1,8,68,712,9270,...] = [1,12,150,2184,37523,...].
		

Crossrefs

Cf. A113340, A113350, A113356 (column 0), A113357 (column 1), A113358 (column 2), A113359 (column 3); A091351.

Programs

  • PARI
    T(n,k)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+1,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(2*j-1))[i-j+1,1]));));A=B); (matrix(#A,#A,r,c,if(r>=c,(A^(2*c))[r-c+1,1]))^2)[n+1,k+1]

Formula

T(n, k) = sum_{j=0..n-k} T(n-k, j)*T(j+k-1, k-1) for n>=k>0 with T(n, 0) = A113346(n+1) - 1, for n>=0.

A113357 Column 1 of triangle A113355, also equals column 0 of A113355^2.

Original entry on oeis.org

1, 8, 68, 712, 9270, 147174, 2786270, 61662544, 1568627031, 45226595865, 1460494997316, 52298603045920, 2059014449303471, 88476000281671109, 4123177399591735062, 207239886694280045429, 11179817701706220363653
Offset: 0

Views

Author

Paul D. Hanna, Nov 08 2005

Keywords

Comments

A113355 equals the matrix square of A113350, where column 1 of A113350^2 = column 0 of A113350^4.

Crossrefs

Cf. A113340, A113350, A113355, A113356 (column 0), A113358 (column 2), A113359 (column 3).

Programs

  • PARI
    a(n)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+2,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(2*j-1))[i-j+1,1]));));A=B); (matrix(#A,#A,r,c,if(r>=c,(A^(2*c))[r-c+1,1]))^2)[n+2,2]

A113358 Column 2 of triangle A113355, also equals column 0 of A113355^3.

Original entry on oeis.org

1, 12, 150, 2184, 37523, 754171, 17502145, 462930509, 13792292332, 458112945183, 16812390472566, 676432435584855, 29635374525536866, 1405425902409792025, 71770681806834337871, 3928431507732054301085, 229528875492540329214765
Offset: 0

Views

Author

Paul D. Hanna, Nov 08 2005

Keywords

Comments

A113355 equals the matrix square of A113350, where column 2 of A113350^2 = column 0 of A113350^6.

Crossrefs

Cf. A113340, A113350, A113355, A113356 (column 0), A113357 (column 1), A113359 (column 3).

Programs

  • PARI
    a(n)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+3,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(2*j-1))[i-j+1,1]));));A=B); (matrix(#A,#A,r,c,if(r>=c,(A^(2*c))[r-c+1,1]))^2)[n+3,3]

A113359 Column 3 of triangle A113355, also equals column 0 of A113355^4.

Original entry on oeis.org

1, 16, 264, 4912, 104476, 2531004, 69265724, 2122120824, 72160283026, 2702008172582, 110631977612048, 4922281897250776, 236665779016591350, 12236187035970192634, 677311496213007409312, 39980910968200568816168
Offset: 0

Views

Author

Paul D. Hanna, Nov 08 2005

Keywords

Comments

A113355 equals the matrix square of A113350, where column 3 of A113350^2 = column 0 of A113350^8.

Crossrefs

Cf. A113340, A113350, A113355, A113356 (column 0), A113357 (column 1), A113358 (column 2).

Programs

  • PARI
    a(n)=local(A,B);A=matrix(1,1);A[1,1]=1;for(m=2,n+4,B=matrix(m,m); for(i=1,m, for(j=1,i,if(i<3 || j==i || j>m-1,B[i,j]=1,if(j==1, B[i,1]=1,B[i,j]=(A^(2*j-1))[i-j+1,1]));));A=B); (matrix(#A,#A,r,c,if(r>=c,(A^(2*c))[r-c+1,1]))^2)[n+4,4]
Showing 1-4 of 4 results.