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.

A104560 Matrix inverse of triangle A104559, read by rows.

Original entry on oeis.org

1, -1, 1, 1, -2, 1, -2, 5, -4, 1, 6, -16, 15, -6, 1, -30, 81, -79, 36, -9, 1, 204, -552, 543, -256, 72, -12, 1, -1944, 5262, -5184, 2461, -712, 132, -16, 1, 23340, -63180, 62260, -29596, 8615, -1640, 220, -20, 1, -360060, 974670, -960520, 456700, -133091, 25475, -3500, 350, -25, 1, 6692280, -18115800
Offset: 0

Views

Author

Paul D. Hanna, Mar 16 2005

Keywords

Comments

Column 0 is A104561.

Examples

			Triangle begins:
1;
-1,1;
1,-2,1;
-2,5,-4,1;
6,-16,15,-6,1;
-30,81,-79,36,-9,1;
204,-552,543,-256,72,-12,1;
-1944,5262,-5184,2461,-712,132,-16,1;
23340,-63180,62260,-29596,8615,-1640,220,-20,1;
-360060,974670,-960520,456700,-133091,25475,-3500,350,-25,1; ...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(M);M=matrix(n+1,n+1,m,j,if(m>=j, binomial(m-1-(j-1)\2,j\2)*binomial(m-1-j\2,(j-1)\2))); return((M^-1)[n+1,k+1])}