A304600 Number of nX4 0..1 arrays with every element unequal to 0, 1, 2, 5 or 6 king-move adjacent elements, with upper left element zero.

8, 9, 23, 73, 179, 515, 1450, 4024, 11122, 31092, 86816, 242134, 674738, 1881798, 5248442, 14637102, 40816980, 113827162, 317437278, 885253890, 2468736666, 6884654742, 19199525352, 53542506842, 149316129526, 416403812262

Offset

1,1

Comments

Column 4 of A304604.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) -5*a(n-3) +4*a(n-4) -4*a(n-5) -29*a(n-6) +18*a(n-7) +16*a(n-8) -7*a(n-9) +30*a(n-10) -8*a(n-11) -24*a(n-12) +12*a(n-13) -20*a(n-15) +12*a(n-17) for n>22

Example

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

Crossrefs

Cf. A304604.

Sequence in context: A046258 A074344 A256932 * A278076 A081351 A032462

Adjacent sequences: A304597 A304598 A304599 * A304601 A304602 A304603

Keyword

nonn

Author

R. H. Hardin, May 15 2018

Status

approved