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.

A223671 Number of 4Xn 0..1 arrays with rows, diagonals and antidiagonals unimodal.

Original entry on oeis.org

16, 256, 1723, 6454, 18980, 49561, 119150, 267643, 567197, 1142224, 2198273, 4062420, 7238132, 12477929, 20877528, 33995513, 54002935, 83867606, 127578211, 190413722, 279263958, 403007495, 572953490, 803354343, 1111996481, 1520876908
Offset: 1

Views

Author

R. H. Hardin Mar 25 2013

Keywords

Comments

Row 4 of A223669

Examples

			Some solutions for n=4
..1..0..0..0....0..1..1..0....0..0..0..0....0..1..1..1....0..0..0..1
..0..1..0..0....0..0..0..0....1..1..0..0....0..1..1..0....0..1..1..0
..0..1..1..1....0..1..0..0....0..0..1..1....1..1..1..0....1..0..0..0
..1..0..0..0....0..0..1..0....0..0..0..0....0..1..1..0....0..0..1..0
		

Formula

Empirical: a(n) = (1/112)*n^8 - (19/210)*n^7 + (59/45)*n^6 - (61/120)*n^5 - (8789/144)*n^4 + (99083/120)*n^3 - (10598579/2520)*n^2 + (1548737/140)*n - 11539 for n>6