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.

A223570 Number of n X n 0..2 arrays with antidiagonals unimodal.

Original entry on oeis.org

3, 81, 16038, 16230456, 64207683936, 817235401137408, 28907250609032395776, 2535541672670058530700288, 503424192483622111094950081536, 209983768351036102380925723459562496
Offset: 1

Views

Author

R. H. Hardin Mar 22 2013

Keywords

Comments

Diagonal of A223576

Examples

			Some solutions for n=3
..1..0..2....0..2..1....2..1..2....1..0..2....0..0..0....1..2..0....0..0..0
..1..1..2....1..1..1....2..2..0....1..0..1....0..1..0....0..1..0....1..0..2
..1..1..0....0..0..0....2..1..1....0..1..2....1..1..1....2..0..0....0..0..0
		

Formula

Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24
a(n) = U(n) * product{ U(i)^2 , i=1..(n-1) }