A301780 Number of nX4 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.

8, 128, 1808, 25872, 369936, 5289488, 75632400, 1081436176, 15463010576, 221099215376, 3161406558992, 45203649489936, 646348354426128, 9241868742610448, 132145672330843920, 1889496507915005968

Offset

1,1

Comments

Column 4 of A301784.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 13*a(n-1) +20*a(n-2) -16*a(n-3) -64*a(n-4)

Example

Some solutions for n=5
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0
..0..1..0..1. .0..1..1..1. .1..0..1..1. .0..1..0..0. .0..0..1..0
..1..0..0..0. .0..1..0..1. .0..0..1..0. .1..0..1..1. .1..1..1..0
..0..1..1..1. .1..1..1..0. .0..0..1..0. .0..1..0..1. .1..0..1..0
..1..1..0..0. .1..0..0..0. .0..0..1..1. .1..0..1..0. .1..1..1..1

Crossrefs

Cf. A301784.

Sequence in context: A301439 A302006 A302011 * A348804 A316804 A317521

Adjacent sequences: A301777 A301778 A301779 * A301781 A301782 A301783

Keyword

nonn

Author

R. H. Hardin, Mar 26 2018

Status

approved