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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A136470 Triangle T, read by rows, where column 0 of T^m = {C(m*2^n, n), n>=0} for all m.

Original entry on oeis.org

1, 2, 1, 6, 8, 1, 56, 128, 32, 1, 1820, 6048, 2176, 128, 1, 201376, 912128, 419328, 34816, 512, 1, 74974368, 449708544, 249300992, 26198016, 548864, 2048, 1, 94525795200, 739136655360, 477013868544, 59943682048, 1604059136, 8650752, 8192, 1, 409663695276000, 4132411271661568, 3028532448264192, 439222754869248, 14159357935616, 98723430400, 136839168, 32768, 1, 6208116950265950720, 80121787455478857728, 65415571433959456768, 10679727629898088448, 399723620798038016, 3391703461396480, 6141702569984, 2172649472, 131072, 1
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

Column 0 of T^(n+1) = row 2n+1 of square array A136462 defined by: A136462(n,k) = C((n+1)*2^(k-1), k); T^n denotes the n-th matrix power of this triangle T = A136470.

Examples

			Triangle T begins:
1;
2, 1;
6, 8, 1;
56, 128, 32, 1;
1820, 6048, 2176, 128, 1;
201376, 912128, 419328, 34816, 512, 1;
74974368, 449708544, 249300992, 26198016, 548864, 2048, 1;
94525795200, 739136655360, 477013868544, 59943682048, 1604059136, 8650752, 8192, 1;
409663695276000, 4132411271661568, 3028532448264192, 439222754869248, 14159357935616, 98723430400, 136839168, 32768, 1; ...
Column 0 of T^m is given by: [T^m](n,0) = C(m*2^n, n) for n>=0.
		

Crossrefs

Cf. columns: A014070, A136471, A136472; A136467 (matrix square-root); A136462.

Programs

  • PARI
    {T(n,k)=local(M=matrix(n+1,n+1,r,c,binomial(r*2^(c-2),c-1)),P); P=matrix(n+1,n+1,r,c,binomial((r+1)*2^(c-2),c-1));((P~*M~^-1)^2)[n+1,k+1]}
    for(n=0, 10, for(k=0, n, print1(T(n, k), ", ")); print(""))

Formula

Equals the matrix square of triangle A136467.
Diagonals: T(n+1,n) = 2*4^n; T(n+2,n) = 2*8^n*(2^(n+2) + n-1).

A136472 Column 2 of triangle A136470 (scaled): a(n) = A136470(n+2,2)/4^n.

Original entry on oeis.org

1, 8, 136, 6552, 973832, 465833856, 739387804752, 3992649623654752, 74888425049167499424, 4962998789388515787006336, 1178375010889854741001146703936, 1013755301703927988518902015091910656
Offset: 0

Views

Author

Paul D. Hanna, Jan 01 2008

Keywords

Comments

Triangle T = A136470 is defined by: column 0 of T^m = {C(m*2^n, n), n>=0}.

Crossrefs

Programs

  • PARI
    {a(n)=local(M=matrix(n+3,n+3,r,c,binomial(r*2^(c-1),c-1)),P); P=matrix(n+3,n+3,r,c,binomial((r+1)*2^(c-1),c-1));(P~*M~^-1)[n+3,3]/4^n}
Showing 1-2 of 2 results.