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 1-2 of 2 results.

A184879 Triangular array T read by rows: T(n, k) = Sum_{i=0..2*n-2*k} binomial(2*n-2*k, i)*binomial(2*k, i)*(-1)^i, 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, -2, 1, 1, -1, -1, 1, 1, 4, 6, 4, 1, 1, 13, 2, 2, 13, 1, 1, 26, -17, -20, -17, 26, 1, 1, 43, -39, -5, -5, -39, 43, 1, 1, 64, -36, 64, 70, 64, -36, 64, 1, 1, 89, 36, 116, 14, 14, 116, 36, 89, 1, 1, 118, 237, 8, -238, -252, -238, 8, 237, 118, 1, 1, 151, 643, -395, -358
Offset: 0

Views

Author

Paul Barry, Jan 24 2011

Keywords

Comments

Row sums are in A108474, antidiagonal sums are in A184880.
T(2*n, n) is (-1)^n*A000984, T(2*n ,n)-T(2*n, n+1) is A184881.

Examples

			Triangle begins
  1;
  1,   1;
  1,  -2,   1;
  1,  -1,  -1,   1;
  1,   4,   6,   4,    1;
  1,  13,   2,   2,   13,    1;
  1,  26, -17, -20,  -17,   26,    1;
  1,  43, -39,  -5,   -5,  -39,   43,   1;
  1,  64, -36,  64,   70,   64,  -36,  64,   1;
  1,  89,  36, 116,   14,   14,  116,  36,  89,   1;
  1, 118, 237,   8, -238, -252, -238,   8, 237, 118,   1;
		

Crossrefs

Programs

  • Magma
    &cat[ [ &+[ Binomial(2*n-2*k, i)*Binomial(2*k, i)*(-1)^i: i in [0..(2*n-2*k)] ]: k in [0..n] ]: n in [0..11] ]; // Klaus Brockhaus, Feb 10 2011

Extensions

Edited by Klaus Brockhaus, Feb 10 2011

A184882 a(n)=1-4*n-4*n^2.

Original entry on oeis.org

1, -7, -23, -47, -79, -119, -167, -223, -287, -359, -439, -527, -623, -727, -839, -959, -1087, -1223, -1367, -1519, -1679, -1847, -2023, -2207, -2399, -2599, -2807, -3023, -3247, -3479, -3719, -3967, -4223, -4487, -4759, -5039, -5327, -5623
Offset: 0

Views

Author

Paul Barry, Jan 24 2011

Keywords

Comments

Hankel transform of A184881.

Programs

Formula

G.f.: (1-10*x+x^2)/(1-x)^3.
a(n)=+3*a(n-1)-3*a(n-2)+1*a(n-3) for n>=3.
a(0)=1, a(n)=a(n-1)-8*n. - Vincenzo Librandi, Jan 25 2011
Showing 1-2 of 2 results.