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.

A144092 Triangle of Hankel transforms of sequence array of C(n,floor(n/2)).

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, -1, 1, 1, 1, 0, 2, 0, 1, 1, 1, 2, -4, 2, 1, 1, 0, 3, 0, 10, 0, 1, 1, -1, 3, 9, 15, -25, 5, 1, 1, 0, 4, 0, 42, 0, 70, 0, 1, 1, 1, 4, -16, 56, 196, 196, -196, 14, 1, 1, 0, 5, 0, 120, 0, 1176
Offset: 0

Views

Author

Paul Barry, Sep 10 2008

Keywords

Comments

The parity matrix A144093 of this array seems to have row sums A061338(n+1).

Examples

			Triangle begins
1,
1, 1,
1, 0, 1,
1, -1, 1, 1,
1, 0, 2, 0, 1,
1, 1, 2, -4, 2, 1,
1, 0, 3, 0, 10, 0, 1,
1, -1, 3, 9, 15, -25, 5, 1,
1, 0, 4, 0, 42, 0, 70, 0, 1,
1, 1, 4, -16, 56, 196, 196, -196, 14, 1,
1, 0, 5, 0, 120, 0, 1176, 0, 588, 0, 1
		

Formula

Triangle (-1)^C(k+1,2)*H(n,k) where the k-th column of H(n,k) is the Hankel transform of the k-th column of the array [k<=n]*C(n-k,floor((n-k)/2).