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.

A219003 Unmatched value maps: number of 2 X n binary arrays indicating the locations of corresponding elements not equal to any horizontal, diagonal or antidiagonal neighbor in a random 0..2 2 X n array.

Original entry on oeis.org

1, 10, 46, 163, 604, 2341, 9019, 34489, 131968, 505576, 1936801, 7418188, 28412533, 108826777, 416833201, 1596565270, 6115202470, 23422612879, 89713931536, 343624709737, 1316160560251, 5041193495617, 19308914689348, 73957523312800
Offset: 1

Views

Author

R. H. Hardin, Nov 09 2012

Keywords

Comments

Row 2 of A219002.

Examples

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

Crossrefs

Cf. A219002.

Formula

Empirical: a(n) = 4*a(n-1) - 3*a(n-2) + 9*a(n-3).
Empirical g.f.: x*(1 + 3*x)^2 / (1 - 4*x + 3*x^2 - 9*x^3). - Colin Barker, Jul 25 2018