A300468 Number of nX4 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

8, 108, 925, 8608, 80914, 759100, 7121067, 66808673, 626787854, 5880428484, 55169285001, 517589818216, 4855948719471, 45557770236528, 427416051858041, 4009952208993844, 37620760026099796, 352952232638874508

Offset: 1

Author

R. H. Hardin, Mar 06 2018

Keywords

• nonn

Comments

Column 4 of A300472.

Examples

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

Links

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

Crossrefs

Cf. A300472.

Formula

Empirical: a(n) = 9*a(n-1) +6*a(n-2) -25*a(n-3) +20*a(n-4) +29*a(n-5) -96*a(n-6) -202*a(n-7) -25*a(n-8) +97*a(n-9) +311*a(n-10) +107*a(n-11) -106*a(n-12) +1300*a(n-13) -663*a(n-14) +910*a(n-15) -317*a(n-16) +343*a(n-17) -96*a(n-18) +57*a(n-19) -29*a(n-20) -4*a(n-22)