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.

A208503 Number of 5 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 0 and 1 1 1 vertically.

Original entry on oeis.org

13, 169, 234, 650, 1794, 4992, 13806, 38376, 106236, 295074, 817362, 2269098, 6288048, 17450550, 48371544, 134210700, 372088314, 1032237882, 2862135666, 7939298016, 22015398366, 61064779464, 169339275612, 469681757298
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2012

Keywords

Comments

Row 5 of A208501.

Examples

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

Crossrefs

Cf. A208501.

Formula

Empirical: a(n) = a(n-1) + 6*a(n-2) - 3*a(n-3) for n>5.
Empirical g.f.: 13*x*(1 + 12*x - x^2 - 43*x^3 + 19*x^4) / (1 - x - 6*x^2 + 3*x^3). - Colin Barker, Jul 03 2018