A303465 Number of nX4 0..1 arrays with every element equal to 0, 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

8, 105, 948, 9110, 89371, 872026, 8511918, 83188773, 812770434, 7941139206, 77594942021, 758189368200, 7408382994582, 72388855049517, 707326301400014, 6911432717332626, 67533080382574931, 659880121609889226

Offset: 1

Author

R. H. Hardin, Apr 24 2018

Keywords

• nonn

Comments

Column 4 of A303469.

Examples

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

Links

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

Crossrefs

Cf. A303469.

Formula

Empirical: a(n) = 12*a(n-1) -15*a(n-2) +6*a(n-3) -854*a(n-4) +1079*a(n-5) +2906*a(n-6) +9224*a(n-7) -20608*a(n-8) -22133*a(n-9) -8708*a(n-10) +56172*a(n-11) -22130*a(n-12) -37398*a(n-13) +204184*a(n-14) -19940*a(n-15) +45128*a(n-16) -220512*a(n-17) +7920*a(n-18) -23328*a(n-19) +46656*a(n-20) for n>21